Police and criminal justice co-operation after Brexit

ABSTRACT The article will evaluate the current state of UK-EU police and criminal justice cooperation and its implications for UK criminal justice policy. The article will place current developments within the broader historical and constitutional context of the ambivalent UK participation in the EU area of criminal justice before Brexit and highlight the significance of criminal justice and police practitioners in shaping UK European policy in the field. The article will map the constitutional evolution of the UK position in the field and assess the relevance of pre-Brexit challenges to the post-Brexit era. Looking at both how UK policy has been influenced – and has in turn influenced – EU criminal justice policy, the article will evaluate the provisions of the TCA and focus on key current challenges, including the constitutional constraints underpinning UK participation in EU police and criminal justice structures after Brexit, the challenge of regulatory divergence in the field (in particular regarding data protection) and the development of mutual trust and credible benchmarks of collaboration (including compliance with European human rights norms) after Brexit.


Introduction
The withdrawal of the UK from the European Union has posed significant challenges to police and criminal justice cooperation.While European integration in criminal matters has been seen as an anathema to many in the UK sceptical of the development of European integration beyond free movement and the internal market, the United Kingdom has both contributed and participated widely in the development of a number of intra-EU police and criminal justice cooperation mechanisms as an EU Member State.The actual contribution of the UK in the construction of the EU's area of criminal justice challenges the general perception of the UK as an 'awkward partner' in European integration, (on challenges to the perception of the UK as an 'awkward partner' see Richardson & Rittberger, 2020).The present contribution will evaluate the current, post-Brexit state of UK-EU police and criminal justice cooperation and its implications for UK criminal justice policy.
The article will place current developments within the broader historical and constitutional context of the ambivalent UK participation in the EU area of criminal justice before Brexit and highlight the significance of a number of actors, including criminal justice and police practitioners (high users of EU cooperation mechanisms and structures before Brexit) in shaping UK European policy in the field.The article will map the constitutional evolution of the UK position in the field and assess the relevance of pre-Brexit challenges for the post-Brexit era.Looking at both how UK policy has been influencedand has in turn influenced -EU criminal justice policy, the article will evaluate the provisions of the Trade and Cooperation Agreement (TCA) and focus on key current challenges for cooperation.These include the constitutional constraints underpinning UK participation in EU police and criminal justice structures after Brexit, the challenge of regulatory divergence in the field (in particular regarding data protection) and the development of mutual trust and credible benchmarks of collaboration (including compliance with European human rights norms) after Brexit.

The Europeanisation of criminal law
The development of EU criminal law has been one of the fastest growing fields of cooperation and law in the EU over the past twenty years.From the introduction of a competence in 1999 in the Amsterdam Treaty, the subsequent treaty amendments have consistently widened the EU's powers in the area.It is one where constitutional normalization is clearly demonstrated (in the constitutional evolution and substantive content of EU Criminal Law and Justice see Mitsilegas, 2022).While at the UK's suggestion, in 1999, the area was not one of harmonization but rather of cooperation through mutual recognition, the shortcomings of such an approach were rapidly apparent with the negotiation of the European Arrest Warrant (still a cornerstone of EU law in the field), a mechanism for replacing extradition among the Member States (Mitsilegas, 2006;Marin, 2008).The need to effectively develop some way to 'harmonise' the list of offences, across the Member States, for which the EAW would be applicable indicated the inextricability of mutual recognition with harmonization.Further, the transformation of what had been extradition from a political decision to deliver a suspect to another country for prosecution or punishment, taken in the final instance by the executive, to one where the judges had the final say, was also profound (Mancano, 2021).It meant that the focus of the attention of the criminal justice system and NGOs was no longer on the workings of the executive but on the robustness of the criminal justice system in the Member State where the requesting decision was taken.This meant that for all the grand claims to reinforce mutual trust, increasingly the weaknesses of systems in Member States became the main obstacles to transfer (for instance the cases of extradition to Poland which British judges blocked on the basis of the inadequacies of the Polish penal system) (Christou et al., 2010;Czerniak, 2022).
Not only has the field of criminal justice be a rapidly growing one, it has also encompassed ever more areas of application.As the EU has adopted an ever-larger acquis in key areas of criminal law and governance is has branched into a myriad of areas.While it started with the harmonization of substantive criminal law and judicial cooperation on the basis of mutual recognition and mutual trust throughout the criminal process (of which the EAW is emblematic) these developments created serious concerns for the rights of defendants.Accordingly, in a spill-over process which has not been necessarily foreseen by those advocating forms of intergovernmental criminal justice cooperation, reflecting thus the law of unintended consequences, the EU moved towards the harmonization of criminal procedure, in particular defence rights to accompany the operation of mutual recognition in criminal matters.European integration extended further to the establishment of a series of institutions (bodies and agenciespresenting their own issues for the coherence of the EU constitutional framework) (Curtin, 1993), to oversee and assist the implementation of the acquis including Eurojust, Europol, the European Public Prosecutor's Office etc. Coordination and the incorporation into law of informal network relationships was also a feature of development in the field.Law enforcement cooperation and exchange of persona data were set out in EU measures.Similarly, aspects of surveillance, in particular the development of systems of exchange of Passenger Name Records (PNR) (Brouwer, 2009) and data retention, were the subject of formal measures and substantial judicial consideration (Mitsilegas, 2022;Fennelly, 2019).
The evolution of European integration in criminal matters is differentiated from many other areas of European integration in that EU action has a direct impact on individual rights.The development of Europe's area of criminal justice has been strongly and overtly underpinned by EU fundamental rights protection considerations.The entry into force of the Lisbon Treaty constitutionalized police and judicial cooperation in criminal matters, most notably by affirming the constitutional status and applicability of the Charter of Fundamental Right (Mitsilegas, 2016).Title VI of the EU Charter of Fundamental Rights is specifically designed to protect rights in the context of criminal justice.While it includes all of the rights contained also in the ECHR, nonetheless, the wording is slightly different in the case of some provisions and the rights are wider than those in the ECHR (Peers et al., 2021).The CJEU has been required to consider numerous questions regarding the correct interpretation of EU criminal law and has relied extensively on the Charter for guidance (Marguery, 2012).These principles have also been key to the development of the external dimension of EU criminal law.This is particularly important now that the UK has become a third country for the purposes of EU criminal law.

The UK's position in the development of EU criminal law
In the pre-Brexit era, the UK developed an ambivalent relationship with the evolution of European integration in criminal matters (Mitsilegas, 2016).This ambivalence was premised on the clash between the focus by the UK on effectiveness of law enforcement and security cooperation and the use of the EU legal framework to achieve such effectiveness on the one hand, and concerns regarding the adverse impact of integration in the sensitive area of criminal law on state sovereignty on the other.The position of the UK in the development of EU criminal law reflects a paradox: on the one hand, politically, European integration in criminal matters has been viewed and presented in political rhetoric as an undesirable incursion into state sovereignty; on the other hand, operationally, UK participation in EU criminal law legislation and structures of cooperation was viewed as highly desirable in terms of the effectiveness of security and law enforcement.To analyse the post-Brexit legal landscape of EU-UK cooperation it should not be forgotten that, as has been pointed out by the House of Lords European Union Committee, the UK has been a leading protagonist in driving and shaping the nature and direction of cooperation at EU level on police and security matters (House of Lords European Union Committee , Brexit: future UK-EU security and police cooperation, 7th Report, session 2016-17, para.27).A key example in this context has been the United Kingdom's leadership in securing the application of the principle of mutual recognition in the field of criminal law, an idea which was put forward by the then UK Home Secretary Jack Straw at the Cardiff European Council in 1998.This initiative is emblematic of the UK approach towards European integration in criminal matters: the UK has pushed for a system based on automaticity in inter-state cooperation, granting extraterritorial reach to national decisions, without this being envisaged to require initially any EU harmonization in the fieldwith EU Member States thus not having to change their domestic criminal laws in order to comply with Brussels-led legislation (Mitsilegas, 2009).On the other hand, the UK has been reluctant to adopt EU legislation which would have an impact on domestic criminal procedure, in particular in the field of defence rights (Mitsilegas, 2016).The UK has also led in the development of an EU model of data-driven law enforcement and surveillance.Key examples include the export of a model of intelligence-led policing to Europol (Mitsilegas, 2017: UK officials have also held two Eurojust Presidencies (including the inaugural Presidency) and a key Directorship of Europol) and the adoption of the controversial data retention Directivewhich reflects a UK focus on largescale surveillance (Mitsilegas, 2021).
Yet these efforts by the UK to influence European criminal law have been combined by fears, at the political level, that European integration in criminal matters would threaten unduly state sovereignty.These fears were exacerbated by the changes in the constitutional framework underpinning criminal law brought about by the Lisbon Treaty, signifying in particular the end of unanimity in the Council and full powers for the Commission and the CJEU in the field of criminal law.The entry into force of the Lisbon Treaty has thus led to efforts by the UK to extend the pre-Lisbon provisions enabling UK 'opt-outs' in the field of EU migration law to the field of EU criminal law.Protocol 21 to the Lisbon Treaty extended the right of the UK not to participate in EU law to the whole of Title V TFEU on the Area of Freedom, Security and Justice, including criminal law measures (Protocol 19 covers the United Kingdom's participation regarding the Schengen acquis.).The right not to participate also extended to legislation amending existing measures which were binding upon the UK.The UK government would decide on its participation in post-Lisbon measures on a case-by-case basis (See Articles 3 and 4 of Protocol no 21).The Lisbon Treaty has also introduced the legal possibility for the development of EU criminal justice à-la-carte, in the Treaty legal basis enabling the establishment of a European Public Prosecutor's Office.Reflecting Member States' concerns over the impact of such an agency on national sovereignty and legal diversity, Article 86 TFEU introduced an exception to the ordinary decision-making procedure by requiring the establishment of the Office by enhanced cooperation.The UK announced from the outset its non-participation in the Regulation establishing the European Public Prosecutor's Office (The European Union Act 2011 imposes a 'referendum lock' on the UK's participation on the EPPO -European Union Act 2011, cl 11, s 6 and in particular s 6(5)(c).Spencer, 2015).
The UK had a mixed record regarding participation in post-Lisbon EU criminal law pursuant Protocol 21.In the field of mutual recognition, the UK participated in the one major judicial cooperation instrument adopted after Lisbon, the Directive on the European Investigation Order (Directive 2014/ 41/EU of the European Parliament and of the Council of 3 April 2014 regarding the European Investigation Order in criminal matters, [2014] OJ L 130/1).The UK participation in the Directive on the European Investigation Order may be seen to have come against the odds in view of the increasingly Euro-sceptic political climate at Westminster but may be explained by the necessity to ensure that the UK remains in the first category of countries in an increasingly integrated system of judicial cooperation in the field of evidence (House of Commons European Scrutiny Committee, 'The European Investigation Order and Parliamentary Scrutiny of Opt-in Decisions, Oral Evidence of Theresa May', HC 1416, Published on 15 September 2011, Q1: 'what we found was that the police were saying to us that they felt the EIO would be of significant benefit to them.Indeed, there was a concern that, if we were not part of the EIO, what we would see was that the requests from the UK would, frankly, go to the bottom of the pile in future, in relation to assistance that they wanted from police forces in other Member States'.This move reflects a recognition of the functional necessity of being 'in the system' of EU-wide cooperation, which superseded political sovereignty concernsa recognition which as will be seen below remains post-Brexit in relation to a number of areas of EU criminal law.Less encouraging were the signs with regard to the UK participation in post-Lisbon EU criminal procedural law measures granting rights to individuals.While the UK opted into the first measures adopted post-Lisbon on the rights of suspects and defendants in criminal procedure, it did not participate in other key instruments in the field, including in particular the Directive on the right of access to a lawyer (Giannoulopoulos, 2016).The non-participation of the UK in this measure could come as a surprise given the fact that the Directive introduces minimum standards which would arguably lead to minimumif anylegislative changes to domestic criminal procedure (Baroness Ludford has pointed out that UK concerns have been taken into account in negotiations: Oral evidence by Dominic Raab MP to the Justice Sub-Committee of the House of Lords Select Committee on the European Union, Directive 2013/48/EU on the right of access to a lawyer, Tuesday 19 January 2016, Q3).
However, non-participation may be explained by the Government's reluctance to participate in a constitutionalized post-Lisbon framework where institutions such as the Commission and the Court of Justice would have a say in evaluating the domestic implementation and proceeding to the interpretation of the terms of the Directive (The impact of the Court of Justice was a recurring theme in the Oral evidence by Dominic Raab MP to the Justice Sub-Committee of the House of Lords Select Committee on the European Union, Directive 2013/48/EU on the right of access to a lawyer, Tuesday 19 January 2016, QQ 2,3 and 6.The Government's review of the Balance of Competences in the field of criminal justice included an extensive section on the potential impact of the Court of Justice in the field post-Lisbon -HM Government, Review of the Balance of Competences between the United Kingdom and the European Union.Police and Criminal Justice, December 2014, paragraphs 3.11-3.21.)Here, sovereignty concerns related to the impact of EU institutions on the UK legal order supersede calls to participate in EU criminal law.Governmental concerns over the impact of participation in post-Lisbon EU criminal law in terms of the impact on domestic law in the light of judicial scrutiny by the Court of Justice also explains the tendency by the UK Government not to opt into the text of the Commission proposals, but rather to try to influenceto the extent possiblenegotiations and opt in post-adoption if the adopted measure appeared to be acceptable to the UK.This is the strategy that the UK has followed in relation to measures including the Directive on trafficking in human beings (DIRECTIVE 2011/36/EU on preventing and combating trafficking in human beings and protecting its victims, and replacing Council Framework Decision 2002/629/JHA, [2011] OJ L 101/1.) to which the UK opted in post-adoption (See statement by Damian Green, Hansard, 9 May 2011, col.977: 'we chose not to opt in to the directive when it was initially put on the table last summer, because the draft text had to go through an extensive period of negotiation between the European Council and the European Parliament.We wanted to be absolutely sure that the text would not change during those negotiations in a way that would be detrimental to the integrity of the UK's criminal justice system.We wanted to consider a final text that had no risks attached and would not fundamentally change the UK's already strong position in the fight against human trafficking'.).
This 'wait and see' strategy is increasingly coupled with a strategy attempting to broaden the field of the measures where the UK 'opt-out' applies.In the field of international agreements, the UK argued that Articles 1 and 2 of Protocol no 21 were 'not restricted to provisions in agreements concluded under a Title V legal base, but to those adopted or concluded 'pursuant to' Title V'. (House of Lords European Union Committee, The UK's Opt-In Protocol: Implications of the Government's Approach, 9th Report, Session 2014-15, HL Paper 136, paragraph 38.).
UK concerns regarding the impact of the entry into force of the Lisbon Treaty on the transfer of sovereign powers to the European Union in the field of criminal justice have resulted in a further political compromise in the Treaty of Lisbon, which addressed measures which had been adopted before the entry into force of the Lisbon Treaty, under the largely intergovernmental third pillar.Protocol No 36 on Transitional Provisions retained the pre-Lisbon limited powers of EU institutions with regard to third pillar law for a period of five years after the entry into force of the Lisbon Treaty (Hinarejos et al., 2012).At least six months before the end of that period the UK could notify to the Council its non-acceptance of the full powers of the EU institutions in third pillar law (Article 10).In case of a decision not to accept these powers, third pillar law ceases to apply to the UK (Article 10(4)), but the latter may notify subsequently its wish to participate in such legislation which has ceased to apply to it (Article 120( 5)).This transitional period came to an end on 1 December 2014, a date that marked a significant step forward towards the constitutionalization of EU criminal law by granting EU institutions their full powers of scrutiny with regard to third pillar law still in force after Lisbon.
It is important to pay attention to the decisions made by the UK Government after the expiry of the five year deadline set out in the Transitional Provisions Protocol (Mitsilegas et al., 2014).The UK notified the Presidency of the EU that, pursuant to Article 10(4) of Protocol 36, it did not accept the powers of the EU institutions; accordingly, third pillar law would cease to apply in the UK from 1 December 2014 (Council document 12750/13).However, the UK eventually indicated that it would seek to opt back into 35 of third pillar measures including the European Arrest Warrant Framework Decision (Framework Decision 2002/584/JHA of 13 June 2002 on the European Arrest Warrant [2002] OJ L 190/1).In this manner, the UK Government attempted to reconcile the sovereignty-effectiveness paradox: politically, it could argue that it has maintained sovereignty by opting out of the whole of the EU pre-lisbon acquis on criminal law rather than accepting the extended powers of EU institutions in the field; operationally, the UK government could still argue that it takes concerns of practitioners fully into account, and that national security would not be jeopardized as the UK would continue to participate fully in key EU mechanisms of judicial and law enforcement cooperation.
The five-year transitional period expired at the end of November 2014 and the continuation of the applicability of these 35 measures to the UK has been confirmed.Third pillar law will continue to apply to the UK vis-à-vis the vast majority of measures applying the principle of mutual recognition in criminal matters (including the Framework Decision on the European Arrest Warrant) and a number of other key measures including legislation establishing Europol and Eurojust and legislation on joint investigation teams and criminal records (See Annex to Decision 2014/836/EU, [2014] OJ L343/11).Third pillar law which has ceased to apply to the UK following the expiry of the transitional period included inter alia a number of measures on substantive criminal law, the Council Framework Decision on prevention and settlement of conflicts of jurisdiction, and the Framework Decision on the mutual recognition of probation decisions (Notice 430/03, [2014] OJ C430/17).
As was the case with the UK's decision to participate in the post-Lisbon Directive on the European Investigation Order, the 'opting-back-into' the Framework Decision on the European Arrest Warrant was supported by a number of relevant stakeholders and practitioners in the field of criminal justice (House of Commons Home Affairs Committee, Pre-Lisbon Treaty EU police and criminal justice measures: the UK's opt-in decision, paragraphs 8-12 (May, 2014)).In this manner, operational concerns by criminal justice practitioners prevailed over political party ideology.Similarly, views of law enforcement practitioners were taken into account by the UK Government in its subsequent decision for the United Kingdom to opt back into a series of measures related to the Prüm system of storage and exchange of personal data, including DNA data (COUNCIL DECISION 2008/

The actors for future cooperation: the TCA and criminal justice
There are many actors who have a part in future cooperation between the UK and the EU in this area.Among the most important are criminal law practitioners themselves.For the House of Lords' EU Committee's report Beyond Brexit: policing, law enforcement and security in 2021 (https://committees.parliament.uk/publications/5298/documents/52902/default/ [accessed 9 August 2022]), the Committee took oral evidence mainly from state practitioners and policy makers.Without exception these witnesses stressed the importance of effective continuing cooperation with the EU in all areas of criminal justice (as well as law enforcement in the form of border controls) (See for example the evidence of Assistant Chief Constable Peter Ayling, National Police Chiefs' Council and Vice-Admiral Sir Charles Montgomery KBE ADC, Former Director-General, UK Border Force).The perspective of these actors has been important to the general approach of the UK authorities as reflected in the TCA.In a continuum to their pre-Brexit stance, key operational actors in the criminal justice field have sustained calls in favour of a close UK relationship with the EU after Brexit.
After the Brexit referendum, the key question in the field of criminal law has been the extent to which the EU-UK post-Brexit arrangements could replicate the pre-Brexit status quo.Maintaining close cooperation in the field of law enforcement and criminal justice cooperation was a priority for the UK.The willingness of the UK Government to continue participating in co-operative arrangements in the post-Brexit era has been expressed in a variety of ways by then Secretary of State for Exiting the European Union David Davis (According to David Davis, 'maintaining strong security co-operation we have with the EU' as one of the Government's top four overarching objectives in negotiations and future relationship with the EU ', HC Deb, 12 October 2016, col 328.), by then Prime Minister Theresa May ('I therefore want our future relationship with the European Union to include practical arrangements on matters of law enforcement and the sharing of intelligence material with our EU allies' -PM Speech, The Government's negotiating objectives for exiting the EU, 17 January 2017), and enshrined in the Government's White Paper on Brexit ('As we exit, we will therefore look to negotiate the best deal we can with the EU to cooperate in the fight against crime and terrorism.WE will seek a strong and close future relationship with the EU, with a focus on operational and practical cross-border cooperation' -The United Kingdom's Exit from and new partnership with the European Union, Presented to Parliament by the Prime Minister February 2017, Cm 9417).
This political impetus reflected also a strong operational push from UK authorities in favour of maintaining a close relationshipemanating from the acknowledgement that the UK is a leading contributor to and user of EU criminal justice cooperation mechanisms.It has been noted that the UK was one of the highest contributors to EU security co-operation as regards contributions to Europol and its databases (The National Crime Agency pointed out that the UK was 'the second-largest contributor in Europe' to the Europol Information System, and that it led on 'four or five' of the 13 EMPACT [European Multidisciplinary Platform Against Criminal Threats] projects, which coordinate actions by Member States and EU organizations against threats identified by Europol in its Serious and Organised Crime Threat Assessment.evidence to House of Lords European Union Committee, Brexit: Future UK-EU Security Cooperation, Q19) and to the Schengen Information System (According to Security Commissioner Julian King, the UK has over 160,000 alerts on SIS II platformevidence to Home Affairs Committee, op.cit., Q86).
Concerns were further raised regarding the adverse impact of Brexit on the UK capacity for intelligence-led policing following the weakening of its position in Europol (See in this context the warning of Rob Wainwright on the adverse security consequences of Brexit for the UK: Brexit would bring serious security consequences -Europol head http://uk.reuters.com/article/uk-britain-eu-europol-idUKKCN0XG16B, 19 April 2016).According to the UK Government, the UK used Europol more than any other country (HM Government, The UK's cooperation with the EU on justice and home affairs, and on foreign policy and security issues, para 1.16.).The UK Government also saw the value in the EU-wide criminal record exchange system, which 'has allowed the police to build a fuller picture of offending by UK nationals and allowed the courts to be aware of the previous offending of EU nationals being prosecuted'.(Command Paper (8671)  The criminal justice systems in Scotland and Northern Ireland (though not that of Wales) are devolved to the Scottish Parliament and the Northern Ireland Assembly.While the UK Parliament is entitled to legislate in this devolved area according to an agreement, it does not (normally) do so without express consent of the legislatures of the two.
Criminal justice cooperation between Northern Ireland and the Republic of Ireland has been a matter of great concern to all parties for many years.The application of the TCA provisions were the subject of substantial examination by the Northern Ireland Affairs Committee of the House of Commons.In a lengthy report published in June 2021(https://committees.parliament.uk/publications/5650/documents/55754/default/ [accessed 9 August 2022]) the Committee notes that the key concerns for Northern Ireland as regards the TCA are cumbersome extradition processes and possible intelligence blind spots for criminals to exploit.While the Committee welcomed the TCA provisions it noted that there would be losses as regards the ease of cross border cooperation between criminal justice authorities even with the new TCA provisions and the administrative bodies created to ensure rapid resolution of issues.A matter of great concern to the Committee was the Commission's Adequacy Decision regarding data protection standards adopted in June 2021.It is beyond the scope of this chapter to examine the immigration carve out in the Adequacy Decision and its possible implications for border control related data sharing here.Suffice it to note that the Committee was particularly attentive to the possible implications for the smooth operation of the UK-Ireland Common Travel Area which is based on extensive data sharing between the two countries.

Police and criminal justice co-operation after Brexitthe legal framework
The investment of the UK in key areas of EU criminal law and internal security and the willingness of both the EU and the UK to achieve a degree of continuity in key areas, seen within the legal and constitutional limits of the EU relations with third countries, have resulted in the Trade and Cooperation Agreement (TCA) which reveals three levels of ambition in EU-UK relations in the field of criminal law and internal securitya high, a medium, and a low level of ambition (Mitsilegas, 2022).The high level of ambition involves a series of areas where the EU and the UK have made every effort to maintainto the extent possible in view of EU constitutional constraintsa similar degree of cooperation to the pre-Brexit eraa move that could be perceived as a 'win-win' situation for both parties in terms of the effectiveness of security cooperation.These areas include surrender after the European Arrest Warrant; the exchange of personal data including PNR data and DNA data following the Prüm model; and cooperation in the field of confiscation of criminal assets.The medium level of ambition is reflected in areas which, while included in the TCA, cooperation falls clearly short in relation to the pre-Brexit era.These areas include mutual legal assistance (where the ambition of speed is not equal to surrender and where there are further fall backs to the Council of Europe framework) and UK participation in criminal justice agencies such as Europol and Eurojustpolitical will and high ambition in this context has been tempered by the clear constitutional constraints of the UK's post-Brexit position as a third country.The third, and low level of ambition, where no provisions are included in the TCA, involves two areas.The first is areas of limited political priority for at least one of the parties (from the perspective of the UK examples include substantive criminal lawthe acquis on which the UK already did not opt back into after the expiry of the deadline in the Transitional Provisions Protocol in 2014certain measures on mutual recognition in criminal matters, and defence rights).Of a greater constitutional significance is the second area: where the UK position as a third state does not allow it to participate in EU law structures, most significantly in EU databases such as the Schengen Information System.
The non-participation of the UK in these structures has a negative impact also in areas where the TCA demonstrates a high level of ambition for future cooperationsomething which is clearly demonstrated in the case of post-Brexit continuation of a European Arrest Warrant-type system.This reflects the high degree of inter-connectedness of the various elements of EU criminal law as positioned within the broader EU constitutional framework-and demonstrates the limits of the UK's position as a third country in relation to the EU post-Brexit.The TCA aims to provide a high degree continuity with the previously applicable European Arrest Warrant (EAW) system.The pre-Brexit terminology of 'surrender' and of an 'arrest warrant' is maintained in the text-the heading of Title VII is 'surrender', the basis of the system is a 'surrender decision' (Article 613) and the objective of UK-EU cooperation is to base extradition on a mechanism of surrender pursuant to an arrest warrant (Article 596).Most importantly, cooperation remains judicial (Article 598(a)) and is intended to be swift (Article 605).Grounds for refusal to execute are limited, largely mirroring the EAW system (Articles 600 and 601).Going further than the EAW system, non-compliance with the proportionality principle may constitute a ground of refusal to recognize and execute an arrest warrant (Article 597( 1)).
This level of ambition is noteworthy.The TCA establishes a system of very close cooperation between the UK and the EU, with the position of the UKas a third countryapproximating to a great extent the position of EU Member States within the system.However, there are a number of areas where the position of the UK as a third state places limits to this approximation.There are three categories of limits at stake: constitutional limits at EU Member States; legal limits at EU level; and political/operational limits in the implementation of the system.In terms of national constitutional limits, the position of the UK as a third state has reinstated national constitutional constraints in a number of EU Member States regarding the surrender of their own nationals, (Article 603(2) TCA and relevant notifications by a number of EU Member States) while inroads to the abolition of the verification of dual criminality have also been introduced (See in particular Article 599(4) of the TCA and relevant notifications by a number of EU Member States).The position of the UK as a third state has also introduced considerable constraints from the perspective of EU law.A key such constraint with operational implications is the fact that the UK no longer has access to EU databases such as the Schengen Information System, the operation of which is crucial in achieving speedy cooperation under the EAW system.With the UK out of SIS II, the UK authorities have attempted to promote the use of Interpol (the Interpol I-24/7 system) as an alternative system which EU Member States can use to notify Arrest Warrants (Northern Ireland Affairs Committee, Cross-Border Co-operation on Policing, Security and Criminal Justice After Brexit (4 th Report, session 2019-21, HC Paper 766), para.59).However, this is far from a straightforward request from an operational perspective (EU Member States would have to duplicate Warrant uploads to SIS II and the Interpol system) and from a fundamental rights perspective (in view of the challenging human rights record of a number of Interpol members and reports of abuse of the Interpol Red Notice alerts system -For a critical view of Interpol governance and the misuse of Interpol Red Notices see House of Commons Foreign Affairs Committee, In the room: the UK's role in multilateral diplomacy First Report of Session 2021-22, para.119).The operational aspect touches upon key day-to-day concerns in the implementation of the system.It remains to be seen whether the authorities of EU Member States receiving Arrest Warrants from the UK and responsible for operating the system will grant the same priority to requests from a third state compared to requests received from authorities of EU Member States.The prioritization of EU requeststo meet the deadlines of the EAW FDmay lead to de facto delays in the processing of UK requests with the UK being downgraded operationally in relation to EU Member States.

The limitations of future cooperation
Key questions on the development of the post-Brexit EU-UK relationship involve the extent to which cooperation will withstand future regulatory divergence and the extent to which the EU will scrutinise the adherence to its internal values and principles in the development of its external action with a third state which is no longer assumed to subscribe to EU benchmarks in full.These questions are of particular relevance in the field of criminal law and internal security, where cooperation may have significant consequences for the protection of fundamental rights and the rule of law.Part III of the TCA contains a specific provision on the protection of human rights and fundamental freedoms in the field of law enforcement and judicial cooperation in criminal matters (Article 524).Cooperation is based on the Parties' and Member States' longstanding respect for democracy, the rule of law and the protection of fundamental rights and freedoms of individuals, including as set out in the Universal Declaration of Human Rights and in the European Convention on Human Rights (ECHR), and on the importance of giving effect to the rights and freedoms in that Convention domestically (Article 524(1)).Respect for and enforcement of the ECHR is thus key for cooperation under the TCA.The Court of Justice has already confirmed the importance of the UK being party to the ECHR for post-Brexit cooperation (Case C-327/18 PPU Minister for Justice and Equality v RO ECLI:EU:C:2018:733.)The European Union may terminate Part III if the UK denounces the ECHR (Article 692(2)).Part III may also be suspended in the event of serious and systemic deficiencies within one Party as regards the protection of fundamental rights or the principle of the rule of law (Article 693(1)).It has been argued that the repeal of the Human Rights Act 1998 could, if not followed by a legislative substitute, be potentially considered as a deficiency big enough to trigger such suspension (Lazowski, 2020).
Part III of the TCA may also be suspended in the event of serious and systemic deficiencies within one Party as regards the protection of personal data, including where those deficiencies have led to a relevant adequacy decision ceasing to apply (Article 693(2)).It includes detailed provisions on the data protection benchmarks applicable to cooperation (Article 525).The establishment by the Commission of data adequacythat the UK offers an adequate level of data protection, interpreted by the CJEU as 'essentially equivalent' to EU data protection law, and entails regular and ongoing monitoring of the systems of third states (Case C-362/14, Maximillian Schrems v Data Protection Commissioner, ECLI:EU:C:2015:650, parsa 75-76)is key in this context.In June 2021, the Commission adopted two adequacy decisions enabling the ongoing flow of personal data between the UK and the EU (COMMISSION IMPLEMENTING DECISION of 28.6.2021pursuant to Regulation (EU) 2016/ 679 of the European Parliament and of the Council on the adequate protection of personal data by the United Kingdom, Brussels, 28.6.2021C(2021) 4800 final; COMMISSION IMPLEMENTING DECISION of 28.6.2021pursuant to Directive (EU) 2016/680 of the European Parliament and of the Council on the adequate protection of personal data by the United Kingdom [law enforcement], Brussels, 28.6.2021C(2021) 4801 final).In its adequacy assessment, the Commission examined the UK's internal legal and institutional framework on data protection, placing emphasis on the UK's adherence to the ECHR and submission to the jurisdiction of the Strasbourg Court (Recitals 120 and 161 respectively).The Commission noted that: In its structure and main components, the UK legal framework applying to data transferred under this Decision is thus very similar to the one applying in the European Union.This includes the fact that such framework does not only rely on obligations laid down in domestic law, that have been shaped by EU law, but also on obligations enshrined in international law, in particular through the United Kingdom's adherence to the ECHR and Convention 108, as well as its submission to the jurisdiction of the European Court of Human Rights.These obligations arising from legally binding international instruments, concerning notably the protection of personal data, are therefore a particular important element of the legal framework assessed in this Decision.(Recital 19 and 20 respectively) This passage is revealing of the EU's approach on post-Brexit cooperation with the UK in the field of internal security and criminal justice, and is reminiscent of the CJEU approach towards post-Brexit cooperation on surrender.The United Kingdom is deemed to be a trusted external partner in view of its participation in the human rights protection system established by the ECHR.Adherence to and compliance with the ECHR emerges as a key benchmark for EU-UK cooperation and suffices to establish trust even in cases of potential shortcomings in the UK system in specific cases.Adherence to the ECHR and to Council of Europe data protection instruments suffices to keep the UK as a member of what the Commission has called the 'European privacy family'but such adherence must be continued and is of particular importance for the stability and durability of the proposed adequacy findings (Commission press release, https://ec.europa.eu/commission/presscorner/detail/en/IP_21_661, Woods (2021)).
Continuous monitoring by the Commission of the application of the legal framework upon which the adequacy Decisions are basedas required by the CJEU in Schremsis a key provision in both Adequacy Decisions (Article 3(1) of both Decisions.The Decisions have an extendable expiry date, 27 June 2025 -Article 4 of both Decisions).This emphasis on continuous monitoring of the UK data protection regime is crucial, but does not assuage concerns regarding the soundness of the Commission's adequacy assessment.A key concern is the compatibility of the UK regime on the bulk collection and retention of data with EU lawin particular following the development of the CJEU case-law in Tele2 and Watson (Article 3(1) of both Decisions.The Decisions have an extendable expiry date, 27 June 2025 -Article 4 of both Decisions), and more recently in Privacy International (Case C-623/17 Privacy International) and La Quadrature du Net and others (Joined Cases C-511/18, C-512/18 and C-520/18 La Quadrature du Net and Others v Premier Ministre and Others ECLI:EU:C:2020:791).It has been demonstrated that subsequent legislative and judicial developments in the UK have not led to full compliance of the UK regime of bulk data collection and retention with EU law (White, 2021).The European Data Protection Board has criticized the Law Enforcement draft Adequacy Decision including on the grounds of the inclusion of an 'immigration exemption' to data protection, (according to Article 1(2) of the Law Enforcement Adequacy Decision, the decision does not cover personal data that is transferred for purposes of United Kingdom immigration control or that otherwise falls within the scope of the exemption from certain data subject rights for purposes of the maintenance of effective immigration control pursuant to paragraph 4 (1) of Schedule 2 to the DPA 2018) on the provisions on onward transfers of data to third countries, and on bulk interceptions (Opinion 14/2021 regarding the European Commission Draft Implementing Decision pursuant to Regulation (EU) 2016/679 on the adequate protection of personal data in the United Kingdom -EDPB, adopted on 13 April 2021, points 12. 14 and 29).
The persistence of a large-scale surveillance regime in the UK casts doubts on the accuracy of the Commission's Adequacy Decisions and may lead to these Decisions being challenged.While internal developments in the UK with regard to the protection and giving effect to fundamental rights domestically and the relationship between the UK and the ECHR will be watched closely, in the short term it is the compatibility of the UK data protection system with EU law which remains one of the key areas of contestation and evaluationwith adequacy assessments also being contingent upon the development of the EU acquis, shaped decisively by the CJEU.

Conclusion: continued alignment of criminal justice or a divorce?
Many actors in the criminal justice field worked hard to ensure that the provisions of the TCA are comprehensive in the field of criminal justice cooperation and mirror as far as possible the pre-Brexit position.However, the underlying logic of the TCA undermines this determination.While Article 5 TCA ('1.Without prejudice to Article SSC.67 of the Protocol on Social Security Coordination and with the exception, with regard to the Union, of Part Three of this Agreement, nothing in this Agreement or any supplementing agreement shall be construed as conferring rights or imposing obligations on persons other than those created between the Parties under public international law, nor as permitting this Agreement or any supplementing agreement to be directly invoked in the domestic legal systems of the Parties.2. A Party shall not provide for a right of action under its law against the other Party on the ground that the other Party has acted in breach of this Agreement or any supplementing agreement'.) has the general effect of excluding rights for individuals affected by the agreement, the carve out of Part 3, law enforcement and judicial cooperation in criminal matters, means that there is still some scope for individual action as regards the EU.But this is not the case for the UK which is not covered by the carve out.This means that one of the important ways in which interpretation and clarification of EU law takes place, through individual's complaints before national courts which are referred to the CJEU will no longer apply in the UK and no alternative, for instance an action brought by an individual before the UK courts for failure correctly to apply the TCA criminal justice provisions, will be admissible.
On the other hand, cooperation of authorities of EU Member States with the UK is contingent upon the finding that UK law and practice is compatible with EU lawwith judicial authorities of EU Member States having the avenue of referring questions of such compatibility to the CJEU.Thus, divergence seems built into the system.Further, while the TCA generally requires human rights compliance, Article 524 ('1.The cooperation provided for in this Part is based on the Parties' and Member States' long-standing respect for democracy, the rule of law and the protection of fundamental rights and freedoms of individuals, including as set out in the Universal Declaration of Human Rights and in the European Convention on Human Rights, and on the importance of giving effect to the rights and freedoms in that Convention domestically.2. Nothing in this Part modifies the obligation to respect fundamental rights and legal principles as reflected, in particular, in the European Convention on Human Rights and, in the case of the Union and its Member States, in the Charter of Fundamental Rights of the European Union'.)makes cooperation dependent on the protection of fundamental rights including the UDHR and ECHR.As regards the ECHR, the emphasis on domestic implementation is specifically required.At the time of writing, the UK is carrying out a consultation to reform the UK's domestic legislation which incorporates the ECHR and to replace with a Bill of Rights (https://www.gov.uk/government/consultations/human-rights-act-reform-a-modern-bill-of-rights/ human-rights-act-reform-a-modern-bill-of-rights-consultation [accessed 9 August 2022]).There is much debate in the UK legal community about the consequence this change may have on the application of the TCA (https://www.opendemocracy.net/en/bill-repeal-human-rights-act/[accessed 9 August 2022]).
It is evident thus, that a domestic UK agenda of 'de-Europeanisation' (Wolff & Piquet, 2022) leading to divergence in the protection of human rights may arise as a key constitutional obstacle to close police and criminal justice cooperation after Brexit.De-europeanisation here is not merely a process of disengagement from the EU agenda, but an active process of abandoning or diverging from EU norms and benchmarks.In addition to the broader challenges of upholding European benchmarks of human rights protection in the UK, the position of data protection as a key element to cooperation in this field cannot be overemphasized.The EU has built into every part of criminal justice cooperation a requirement that data protection standards in the UK, although no longer bound by the GDPR or the DPD, must correspond to those two EU measures.Should alignment to EU data protection standards in the UK be undermined then data-sharing even in this field will have to cease.While the data subject consent principle of GDPR is not particularly relevant in the criminal justice area, the purpose limitation requirement is very pertinent.This is particularly so as regards data which has been collected in the context of actions outside police operations, such as PNR, border and immigration control data but which are then shared with criminal justice authorities or other state bodies for purposes other than those for which the data was collected.The sensitivity of this issue is underlined in the TCA by the careful circumscription of PNR, border and immigration control related data use to action in respect of terrorism and serious crime (Articles 543-544 TCA) (This is notwithstanding the exception in that article providing that the UK authorities may process PNR data where necessary to protect the vital interests of any natural person).Policing the data protection standards in the UK is the job of the Commission which has been charged with keeping under review the Adequacy Decision.The first decision was adopted by the Commission in accordance with its constitutional requirements on 28 June 2021 and is valid for four years unless the Commission takes steps to curtail it (https://ec.europa.eu/info/sites/default/files/decision_on_the_adequate_protection_of_personal_data_by_the_united_kingdom_law_enforcement_directive_en.pdf [accessed 9 August 2022]).At the time of writing, the Data Protection and Digital Information Bill is before Parliament, the objective of which is to reduce burdens on public and private actors regarding the use of personal data (https://bills.parliament.uk/bills/3322[accessed 9 August 2022]).Its compatibility with the Adequacy Decision will need to be assessed and could well impact the Adequacy Decision for criminal justice purposes.
In this contribution we have examined the impact of Brexit on police and criminal justice cooperation between the UK and the EU.The first important observation is that notwithstanding a substantial amount of ambivalence in British politics about convergence in this field, from its incorporation into EU competence, British practitioners have been very eager to profit from closer cooperation.They have been convinced that the advantages of convergence far outweigh the loss-of-sovereignty disadvantages when it comes to on the ground results in achieving successful policing and cross border cooperation in criminal justice.Secondly, in the negotiation of the TCA, the practitioners far outran their political masters in achieving a surprisingly high degree of continuity in cooperation notwithstanding the generally fairly sour relations within which the Agreement was concluded.Thirdly, there was an impressive unity among the devolved actors within the UK about these objectives.Internal bickering was not evident in this area.Fourthly, what looks likely to become the Achilles heel of cooperation in this field comes from outside it in the form of disputed data protection standards.In the UK's rather febrile political atmosphere where the chimera of potentially enormous financial gains to be made from breaking with EU data protection oriented policy to one of incentivization to the private sector to exploit personal data with new technologies like artificial intelligence and machine learning is dominant, EU-UK police and criminal justice cooperation may become a victim.The success of the British practitioners in the negotiations may yet be undone by commercial policy in a separate field.

Disclosure statement
No potential conflict of interest was reported by the author(s).
615/JHA of 23 June 2008 on the stepping up of cross-border cooperation, particularly in combating terrorism and cross-border crime [2008] L 210/1; COUNCIL DECISION 2008/ 616/JHA of 23 June 2008 on the implementation of Decision 2008/615/JHA on the stepping up of cross-border cooperation, particularly in combating terrorism and cross-border crime, [2008] L 210/12, COUNCIL FRAMEWORK DECISION 2009/905/JHA of 30 November 2009 on Accreditation of forensic service providers carrying out laboratory activities, [2009] L 322/14.)In her speech before the House of Commons, the then Home Secretary Theresa May stressed the views of senior law enforcement officers and stated that attempts to exchange data in other ways would require not only an intergovernmental agreements, but the building of separate systems (House of Commons Hansard Debates for 8 December 2015: Theresa Maycl.914,916 respectively).In a logic of operational necessity, the UK Government thus opted back into the vast majority of the key third pillar law enforcement measures after the expiry of the Transitional Provisions Protocol deadline.
cited in House of Commons European Scrutiny Committee, Exchanging Information on Criminal Convictions, 2 March 2016, para.10.11, http://www.publications.parliament.uk/pa/cm201516/cmselect/cmeuleg/342-xxiii/34213.htm).In addition to the stated value of the Prüm system mentioned earlier in this chapter, UK authorities stressed the importance of continuing to take part in joint investigation teams, (For the principal legal framework, see COUNCIL FRAMEWORK DECISION of 13 June 2002 on joint investigation teams (2002/465/JHA) [2002]OJ L 162/1.) to which UK officers participated extensively (According to the then Director of Public Prosecutions Alison Saunders, 'we get a lot out of joint investigation teams because they help us to make sure that we collect the right evidence.It is much quicker than doing individual letters of request because you collect it all together and it is there; it helps with issues around jurisdiction.It helps with disclosure issues'.evidence to House of Lords EU Committee, Q 54).The capacity to act at a multilateral, transnational level has been highlighted as a key advantage of joint investigation teams (House of Lords EU Committee, paras 74 and 75).UK security professionals also welcomed the adoption of an EU Passenger Name Records (PNR) transfer system (Directive (EU) 2016/681 of the European Parliament and of the Council of 27 April 2016 on the use of Passenger Name Records (PNR) data for the prevention, detection, investigation and prosecution of terrorist offences and serious crime, [2016] OJ L 119/132) as a significant step towards the security of the EU and the UK ('The EU can't dictate to us on security but staying in it can keep us safer' Jonathan Evans and John Sawers (former heads of MI5 and MI6 respectively), The Sunday Times, 8 May 2016.The UK Government said in May 2016 that it had made consistent calls for EU PNR legislation' House of Lords, para 100).