Brexit - Key legislation explained

38 minute read
22 January 2021


11pm (GMT) on 31 December 2020 marked the end of the Brexit transition/implementation period entered into following the UK's withdrawal from the EU. At this point in time (referred to in UK law as "IP completion day"), key transitional arrangements came to an end and significant changes are beginning to take effect across the UK's legal regime. For more information about IP completion day, read our insight What does IP completion day mean for the status of EU law in the UK?

This article explains the key Brexit legislation you need to know and was first published by Lexis Nexis.

Background - EU law in the UK

Pre-exit day

The European Communities Act 1972 (ECA 1972) was introduced and intended to give effect to the UK's obligations as a Member State under the relevant EU treaties to comply with EU law.

Under ECA 1972, s 2(1), certain types of EU rights and obligations, which are intended to be directly effective, were given effect in the UK without the need for any further domestic legislation. This included rights in the EU Treaties as well as EU regulations which contain detailed legal rules.

Other types of EU law were given effect through UK regulations made under ECA 1972, s 2(2), or in some cases through separate Acts of Parliament. This included EU directives which set out broad outcomes or frameworks but which leave it to each Member State to make its own provision to achieve the required legal effect.

In terms of its application in Member States, EU law is 'supreme'. This means that where there is a conflict between EU law and a Member State's domestic legislation, the latter can be disapplied - a principle which provided the only circumstance in which a UK court can disapply an Act of Parliament.

ECA 1972, s 3(1) provided that UK judges were also bound to follow decisions by the Court of Justice of the European Union.

During the 40 or so years of its membership, EU law came to form a large part of the law which applied in the UK, covering a range of different issues. The UK did not therefore need to (and indeed could not) formulate its own domestic laws in relation to such issues where EU law applied directly. Nor could it take a different approach to areas covered by EU directives which required a particular approach to be taken in domestic legislation.

Post-exit day

As of 11pm on 31 January 2020 (exit day), the UK was no longer subject to the EU Treaties as it was no longer an EU Member State. Directly applicable EU law no longer applied to the UK under the EU Treaties as it does for the EU27 Member States, nor was the UK bound by those treaties to ensure that domestic legislation meets the requirements set out in EU directives.

Instead, the UK's relationship with the EU is governed by the Withdrawal Agreement, an international treaty negotiated by the UK and the EU under Article 50 of the Treaty on European Union. The Withdrawal Agreement is intended to:

  1. tie up the administrative and financial loose ends from the UK's membership of the EU
  2. protect UK and EU citizens living in each other's territory, and
  3. provide a stand-still period in relation to the application of EU law in order to allow for the negotiation of a trade deal, referred to in the Withdrawal Agreement as the 'transition period' and in UK legislation as the 'implementation period'

This article will refer to the implementation period as this is the term used in the UK legislation discussed.

On 26 June 2018, the European Union (Withdrawal) Act 2018 (EU(W)A 2018) received royal assent. Its purpose was to repeal the ECA 1972 on exit day and introduce provisions to avoid the legal vacuum that would be created by EU law ceasing to be applicable in the UK, given that much of our law had come from the EU through the EU Treaties. As enacted, the EU(W)A 2018 made no provision for an implementation period, despite the fact that the UK had signalled that it would seek one. 

The European Union (Withdrawal Agreement) Act 2020 (EU(WA)A 2020) was passed on 23 January 2020. The EU(WA)A 2020 contained a mix of amendments to the EU(W)A 2018, together with a number of substantive provisions. It fulfilled two functions:

  1. to amend the EU(W)A 2018 to accommodate the implementation period set out in the Withdrawal Agreement, under which the UK will continue to be bound by EU law (notwithstanding its third country status) until at least 31 December 2020
  2. to make provision in UK law for implementation of other aspects of the Withdrawal Agreement, including provisions on citizens' rights, the financial settlement and the Ireland/Northern Ireland Protocol

This article gives an overview of both the EU(W)A 2018 and the EU(WA)A 2020, as well as highlighting some of their interesting implications from a public law perspective. Given the connection between the two pieces of legislation, rather than discuss each in turn, a thematic approach is taken with discussion first centring on the application of EU-derived law in the UK after Brexit (both during and after the implementation period), before moving on to how other aspects of the Withdrawal Agreement are given effect in domestic law.

EU law in the UK after Brexit

The implementation period - EU legislation

As noted above, the Withdrawal Agreement made provision for an implementation period from the date of the UK's exit from the EU until 11 pm on 31 December 2020. This period was capable of a single extension of either one or two years by mutual agreement between the UK and EU. However, that opportunity was not taken and the implementation period was not extended.

The purpose of the implementation period was to provide a standstill period after the UK officially left the EU during which the UK and EU could negotiate the legal terms of their future relationship and governments, public bodies, businesses and individuals can adapt to the change.

Under the transitional arrangements, apart from participation in EU institutions and governance structures and some other exceptions, the UK was treated as if it continues to be an EU Member State in EU law for the duration of the implementation period. The legal foundation for this was the Withdrawal Agreement rather than the EU Treaties.

The UK remained part of the EU single market and customs union and was required to continue to respect the four freedoms of movement of goods, people, services and capital, as well as continuing to apply the EU customs code to imports into the UK from third countries.

To facilitate this, under the Withdrawal Agreement the UK was required to continue to apply most EU law during the implementation period as if it was still an EU Member State. Any changes or additions to EU law made during the implementation period also applied.

However, prior to the Withdrawal Agreement being finalised, the EU(W)A 2018 made provision for the repeal of the ECA 1972 on exit day.

The effect of repealing the ECA 1972 fully on exit day would mean that directly effective EU law (such as EU regulations) would cease to have effect in the UK and the subordinate legislation made under the ECA 1972 to enact other forms of EU law would also fall away. This did not reflect or give effect to the implementation period, hence the introduction of temporary savings provisions (see below).

Rather than change the definition of exit day under EU(W)A 2018, or postpone the repeal of the ECA 1972, the EU(WA)A 2020 inserted savings provisions into the EU(W)A 2018 on repeal of the ECA 1972, seeking to preserve the effect of certain provisions of the ECA 1972 for the duration of the implementation period, with some amendments as to how those provisions were read. This was to reflect the fact that the UK's relationship with the EU was now governed by the Withdrawal Agreement rather than by virtue of its being an EU Member State.

Up until two years after the end of the implementation period, Ministers and devolved authorities (Scottish and Welsh Ministers and Northern Ireland departments) have the power to make further provision, through subordinate legislation, for the way in which EU law is read during the implementation period. Any regulations made under that power are subject to parliamentary scrutiny using the affirmative resolution procedure (under which each House of Parliament must positively vote to adopt them) where they amend, repeal or revoke primary legislation or an EU regulation that was not tertiary legislation (a delegated or implementing act). Otherwise they are subject to the negative procedure (under which they will continue in effect unless either House votes to annul them within a certain period of time).

The EU(WA)A 2020 also inserted a saving provision to preserve subordinate legislation made under ECA 1972, s 2(2), as well as certain other domestic provisions which give effect to EU law.

Under the Withdrawal Agreement, the UK was required to ensure that the EU law that takes effect in the UK by virtue of the Withdrawal Agreement produced the same legal effects as in EU Member States. This means that:

  1. in certain circumstances individuals and businesses could rely directly on the terms of the Withdrawal Agreement before UK courts
  2. EU law had to prevail over UK domestic law (the principle of supremacy must be maintained), and
  3. provisions of EU law made effective through the Withdrawal Agreement had to be interpreted in line with EU principles

To achieve this, the EU(WA)A 2020 inserted a new provision into the EU(W)A 2018 which gives domestic legal effect to all 'rights, powers, liabilities, obligations and restrictions' created by or arising under the Withdrawal Agreement.

Taken together, the above provisions meant that UK law continued to track relevant EU law as it developed during the implementation period and that EU law remained supreme over domestic law during transition. However, it also means that the relevant 'rights, powers, liabilities, obligations and restrictions' were not set out in the EU(W)A 2018 or the EU(WA)A 2020.

Practitioners first needed to go to the Withdrawal Agreement, and then to the EU law to which it refers, to work out what these rights etc are and how they applied. Although this approach simplified the drafting required in the EU(WA)A 2020, it does make ascertaining the correct legal position more complicated.

Certain new EU laws coming into effect during the implementation period had to be the subject of debate in the House of Commons or the House of Lords where either the Commons European Scrutiny Select Committee or the Lords European Union Select Committee (as relevant) stated that the legislation raises a matter of vital national interest to the UK. However, the UK was obliged to implement any new laws under the Withdrawal Agreement in any event, so any subsequent vote against it would have had no legal effect.

As noted above, under the legislative powers in the EU(W)A 2018, as amended by the EU(WA)A 2020, the UK government and devolved authorities had the power to modify domestic law to ensure continued compliance with EU law during the implementation period. These changes were mostly technical in nature. Such amendments, together with:

  1. the 'rights, powers, liabilities, obligations and restrictions' created by or arising under the Withdrawal Agreement (and rights etc. under the EEA EFTA Separation Agreement and the Swiss Citizens' Rights Agreement), and
  2. any domestic law (including Acts of Parliament and secondary legislation) implementing other parts of the Withdrawal Agreement (apart from Part 4) and the EEA EFTA Separation Agreement and the Swiss Citizens' Rights Agreement

formed a category of law known as 'relevant separation agreement law'.

Any question as to the validity, meaning or effect of any relevant separation agreement law is to be decided:

  1. in accordance with the Withdrawal Agreement, the EEA EFTA Separation Agreement and the Swiss Citizens' Rights Agreement, as relevant, and
  2. having regard (among other things) to the desirability of ensuring consistency between the relevant separation agreement law which implements similar provisions across two or more of those agreements

When considering the interpretation of relevant separation agreement law, practitioners will need to keep track of any decisions by any arbitration panel under the dispute resolution mechanisms in the Withdrawal Agreement, as well as any decisions of the Court of Justice of the European Union on the interpretation of EU law to which the Withdrawal Agreement gives effect.

The implementation period - EU case law

During the implementation period, case law of the Court of Justice of the European Union continued to be applied in the UK as it was before and UK courts could continue to refer cases to the Court of Justice of the European Union.

After the implementation period - retained EU law

The effect of the ECA 1972 in relation to EU legislation, decisions and case law was preserved by the savings provisions introduced by the EU(WA)A 2020 until the end of the implementation period (IP completion day). IP completion day is defined in the EU(WA)A 2020 as 11 pm on 31 December 2020.

On IP completion day, the effect of the ECA 1972 ceased and it no longer serves as the conduit through which EU law takes effect in the UK. However, for the purposes of legal continuity, the legal position existing immediately before IP completion day has been preserved, to a large degree, by taking a snapshot of the EU law that applies in the UK at that point and bringing it within the UK's domestic legal framework as a new category of law-retained EU law.

Retained EU law will be made up of the following four components:

  • EU-derived domestic legislation-secondary legislation made under ECA 1972, s 2(2) and other domestic legislation which implements EU obligations, made prior to IP completion day (this will include provisions in UK primary legislation)
  • direct EU legislation-EU law that has direct effect in the UK prior to IP completion day, such as EU regulations and decisions:
    • retained provisions include those that are in force and apply (ie 'operative') before IP completion day, the effect of which will crystallise later. The explanatory notes to the EU(W)A 2018 give the example of Regulation (EU) 517/2014 on fluorinated greenhouse gases. This Regulation has been in force and applicable since 2015 and prohibits the supply of equipment containing certain substances from specified dates, some of which fall after IP completion day. Because the latter prohibitions are in force they will be retained, even though they will not apply until after IP completion day
    • the EU(W)A 2018 carves out 'exempt EU instruments' excluding certain decisions, and legislation made under those decisions, from the scope
    • where direct EU legislation is retained, it is the English language text of such legislation that will be authoritative
  • any remaining 'rights, powers, liabilities, obligations, restrictions, remedies and procedures' which were available in domestic law through ECA 1972, s 2(1) prior to IP completion day - this includes rights under EU Treaties and directly effective provisions of EU directives which confer rights without the need for domestic implementation. It also includes rights available after the implementation period under the Withdrawal Agreement, and under the EEA EFTA Separation Agreement and the Swiss Citizens' Rights Agreement:
    • rights under EU directives are retained only where they are 'of a kind' recognised by the Court of Justice of the European Union or 'any court or tribunal' in the UK in a case decided before IP completion day. What this will mean in practice is open to debate and is sure to be tested in the courts
  • retained EU case law-principles laid down by, and decisions of, the Court of Justice of the European Union in relation to the above three categories which have effect in EU law before IP completion day, except where excluded by other parts of the EU(W)A 2018

The Charter of Fundamental Rights of the EU does not form part of retained EU law after the end of the implementation period.

In addition, no general principle of EU law has been retained unless it was recognised as such by EU case law before IP completion day and, even where it is retained, following three years from IP completion day, failure to comply with it cannot give rise to a right of action.

Under the Withdrawal Agreement, EU law was intended to continue to apply in the UK only for the duration of the implementation period (although certain aspects of it may apply for longer by virtue of specific separation arrangements for ongoing matters, and in the longer term as specified in any future relationship agreement). Despite this position under the Withdrawal Agreement, the effect of the EU(W)A 2018 is to freeze in place EU law as it applied in the UK immediately before IP completion day. So the law that was intended to apply only during the implementation period continues to have effect indefinitely as retained EU law unless or until it is changed or disapplied as discussed below.

Amending retained EU law

Ministers are given the power to amend retained EU law by regulations where considered 'appropriate' to:

'…prevent, remedy or mitigate

(a) any failure of retained EU law to operate effectively, or

(b) any other deficiency in retained EU law,

arising from the withdrawal of the United Kingdom from the EU.'

The explanatory notes to the EU(W)A 2018 state that the concept of a deficiency is intended to cover circumstances where a retained EU law 'does not function appropriately or sensibly'.

Examples of deficiencies include scenarios where a particular provision is redundant after Brexit, where it confers powers on EU bodies that can no longer exercise those powers in the UK, and where the Minister considers that reciprocal or other arrangements are no longer appropriate, as a result of Brexit.

Regulations made under these powers may make any provision that can be made by primary legislation, thus providing a 'Henry VIII power' to amend Acts of Parliament. However, there are a number of limits imposed on the power to make regulations, including a time limit on the power. The power was due to expire two years after exit day, but was extended under EU(WA)A 2020, to two years after IP completion day.

There is also a list of things that cannot be done through these regulations, such as imposing or increasing taxation, making retrospective provision and creating new criminal offences punishable by imprisonment of more than two years.

In terms of parliamentary scrutiny, the default position is that most regulations made under EU(W)A 2018, s 8(1) are subject to the negative resolution procedure, meaning that they receive scant consideration by Parliament. A small number of regulations are subject to the affirmative resolution procedure and will need to be positively approved by both Houses of Parliament.

'Sifting' committees in both Houses may also recommend that negative regulations should instead be subject to affirmative resolution. However, that recommendation does not have to be followed.

In the relative absence of parliamentary scrutiny, reliance may be placed on the courts to define the parameters within which Ministerial powers can be exercised under EU(W)A 2018, s 8(1). For example:

  • where a process currently set out in EU law is deficient simply because it refers to EU bodies, should a Minister be confined simply to replacing those bodies with UK equivalents?
  • what if the Minister tries to rewrite the process more widely or concentrate power in the hands of one decision-maker where the original process involved input from several stakeholders?

When laying regulations before Parliament a Minister is required to make an explanatory statement:

  • confirming that, in the Minister's opinion, the proposed amendments do no more than is necessary
  • explaining why there is good reason for the amendments and why they are a reasonable course of action, and
  • drawing attention to any amendment, repeal or revocation of equalities law

These statements are intended to aid the parliamentary sifting committees in deciding whether to recommend greater scrutiny for particular regulations. However, where done well they also prove valuable sources of insight into Ministers' reasoning that can be considered by potential challengers and ultimately by the court in deciding whether a particular use of the EU(W)A 2018 powers has been lawful.

Following the passage of the EU(W)A 2018, hundreds of Brexit SIs were made by the government, many of which sought to make provision for a no-deal Brexit at the end of the withdrawal period. The EU(WA)A 2020 provided that those regulations (or parts of them) which were due to come into effect on (or immediately before or after) exit day came into effect on (or immediately before or after) IP completion day, as relevant. However, that default position could be disapplied by regulations.

After the implementation period - EU case law

UK courts are no longer be bound by any principles laid down, or decisions made, by the Court of Justice of the European Union after IP completion day. However, a UK court may have regard to decisions and principles from the Court of Justice of the European Union, as well as anything done by the EU or any of its entities, after IP completion day if it considers it 'appropriate' to do so.

It remains to be seen how the lower courts will interpret 'appropriate' when considering how to treat developments in EU law after the end of the implementation period. However, it is likely that judges will pay greater attention to post-Brexit developments in EU law in areas which are relevant to matters addressed in the future relationship and areas on which that relationship requires consistent/harmonious interpretation.

It will also be interesting to see how the courts will treat the principles of EU law going forward. In EU jurisprudence these are intended to permeate the interpretation of EU law, but some of these principles have been carved out of retained EU law, with the remainder no longer available in terms of a cause of action. It may be that the courts will simply base their decisions on common law principles which mirror EU principles, as the Supreme Court did in R (Unison) v Lord Chancellor. Where a common law analogue cannot be found, EU principles may come to be treated in the same way as customary international law, it used as an aid to interpretation and a source of inspiration for the development of the common law.

Retained EU law is to be interpreted in line with any relevant case law from the EU and UK courts from before IP completion day. This means that UK courts will continue to follow EU case law from before IP completion day where this concerns EU law that has been retained. The following courts may depart from retained EU case law if they consider it right to do so:

  • UK Supreme Court
  • Scottish High Court of Justiciary (where it is the final criminal court of appeal in Scotland where there is no further route of appeal)
  • Court of Appeal of England and Wales
  • Court of Appeal of Northern Ireland
  • High Court of Justiciary (when sitting as a court of appeal in relation to a compatibility issue or a devolution issue)
  • Inner House of the Scottish Court of Session
  • Lands Valuation Appeal Court in Scotland
  • Registration Appeal Court in Scotland
  • Court Martial Appeal Court

Implementing the Withdrawal Agreement

Ratifying the Withdrawal Agreement

As enacted, EU(W)A 2018, s 13 required the government to secure MPs' approval of the Withdrawal Agreement and Political Declaration before the Withdrawal Agreement was ratified. This requirement was removed by the EU(WA)A 2020 together with the application of section 20 of the Constitutional Reform and Governance Act 2010, which would have required the Withdrawal Agreement to be laid before Parliament for 21 sitting days during which time either House could oppose ratification, with MPs able to prevent ratification indefinitely.

These amendments were significant from a public law perspective as they allowed the government to ratify the Withdrawal Agreement with no further input from Parliament once the EU(WA)A 2020 was passed.

Citizens' rights

Under the Withdrawal Agreement, individuals already exercising EU free movement rights in the UK will continue to enjoy certain core rights to reside, work and otherwise remain indefinitely in the UK after the end of the implementation period. References to the Court of Justice of the European Union to enforce those rights may be made up to eight years after the expiry of the implementation period. These rights are mirrored with respect to EEA and Swiss citizens under the EEA EFTA Separation Agreement and the Swiss Citizens' Rights Agreement.

These rights are made directly enforceable in the UK by EU(W)A 2018, s 7A. In addition, the EU(WA)A 2020 provides Ministers with a series of regulation-making powers to:

  • require those protected by the Withdrawal Agreement (and the EEA and Swiss agreements) and others who fall within the EU Settlement Scheme set out in the Immigration Rules (such as those not exercising free movement rights, or who derive their status from a UK citizen) to apply for a UK immigration statu
  • protect 'frontier workers' - those who are economically active, but do not live, in the UK at the end of the implementation period
  • restrict entry and residence of those who would otherwise have those rights on the basis of their actions (including fraud or abuse of those rights) during the implementation period
  • grant a right of appeal to the First-tier Tribunal in relation to certain relevant immigration decisions
  • implement the provisions in the Withdrawal Agreement (and the EEA and Swiss agreements) relating to the recognition of professional qualifications
  • implement provisions in the Withdrawal Agreement (and the EEA and Swiss agreements) relating to social security co-ordination to ensure that persons moving between the UK and EU prior to the end of the implementation period are not disadvantaged in their access to pensions, benefits, and other forms of social security, including healthcare cover, and
  • ensure that UK legislation is consistent with the provisions on non-discrimination and equal treatment in relation to persons residing in the UK in exercise of rights granted under the Withdrawal Agreement (and the EEA and Swiss agreements)

The EU(WA)A 2020 also provides for the establishment of an Independent Monitoring Authority (IMA) to oversee the citizens' rights agreements.

The financial settlement

The EU(WA)A 2020 sets out the mechanisms by which payments will be made between the UK and the EU in accordance with the Withdrawal Agreement. The amount of the payments themselves will be calculated under the procedures specified in the Withdrawal Agreement.

Reporting requirements

The draft version of the EU(WA)A 2020 submitted to Parliament prior to the 2019 general election contained requirements for parliamentary oversight of the negotiations between the UK and EU on the future relationship. These were removed from the version introduced after the election.

In addition, there is no explicit provision for Parliament to scrutinise the government's actions in the Joint Committee established by the Withdrawal Agreement, which oversees its implementation and interpretation. However, the EU(WA)A 2020 inserts a provision into the EU(W)A 2018 to require that the role of the UK co-chair of the Joint Committee is to be undertaken by a Minister. This will allow the UK's main representative on the Joint Committee to be questioned in Parliament, thus affording some degree of oversight.

The EU(W)A 2018 was also amended to require the relevant Minister to be present when decisions or recommendations are adopted by the Joint Committee by precluding the use of the procedure in the Withdrawal Agreement which would allow such actions to be undertaken in writing.

In addition, the government is required to provide a written statement to Parliament where, after the implementation period, an arbitration panel is used or the Court of Justice of the European Union gives a ruling under the dispute settlement mechanism in the Withdrawal Agreement, and to report annually on the numbers of disputes. This will help Parliament keep informed of important decisions by arbitration panels on the interpretation of the Withdrawal Agreement, and hence the interpretation of relevant separation agreement law.

The Protocol on Ireland/Northern Ireland

Under the Withdrawal Agreement, Northern Ireland will remain part of the UK's customs territory and VAT area but will apply EU Single Market rules for goods and remain aligned to EU rules on customs and VAT. The Withdrawal Agreement contains a consent mechanism under which the Northern Ireland assembly will vote every four years on whether to continue to be bound by certain Articles in the Protocol (extendable to eight years where cross-community support is obtained).

Under the EU(W)A 2018, Ministers are empowered to make regulations to implement the Protocol on Ireland/Northern and deal with any matters relating to it. For this purpose, Ministers are given a Henry VIII power to make, through regulations, any provision that could be made by an Act of Parliament, including amending the EU(W)A 2018 itself.

In terms of parliamentary scrutiny, such regulations must be approved in draft under the affirmative resolution procedure in certain circumstances, including where they:

  • amend, repeal or revoke primary legislation or EU regulations which are not tertiary legislation
  • establish a public authority, and/or
  • facilitate the access to the market within Great Britain of qualifying goods from Northern Ireland

In all other cases (including the creation of new criminal offences, retrospective provision and increases in taxation and fees) the negative procedure is used under which the regulations are made subject to annulment by one or the other House of Parliament.

A number of restrictions are placed on these legislative powers, including that Ministers must act in a way that is compatible with the terms of the Northern Ireland Act 1998 (NIA 1998) and must neither diminish North-South co-operation as provided for by the Belfast (Good Friday) Agreement, nor create or facilitate any physical infrastructure on the border between Ireland and Northern Ireland.

Likewise, a Minister may not agree to any recommendation in the Joint Committee that would alter arrangements for North-South co-operation, establish any new North-South implementation body or change the functions of any existing implementation body. The devolved administrations are given parallel regulation-making powers to those given to Ministers, with similar restrictions.

The Withdrawal Agreement requires that there is 'no diminution of rights, safeguards or equality of opportunity' as set out in the Belfast (Good Friday) Agreement because of Brexit. It also provides for a number of EU directives in relation to equality and non-discrimination to continue to apply in Northern Ireland indefinitely. These requirements are implemented through the EU(WA)A 2020 by way of amendments to the NIA 1998, which restrict the legislative competence of the Northern Ireland Assembly to pass any law which is incompatible with the relevant provisions of the Protocol and provide the Northern Ireland Human Rights Commission and the Equality Commission of Northern Ireland with additional functions in this regard.

Other separation issues

Ministers have broad powers to make such regulations as they deem 'appropriate' to implement Part 3 of the Withdrawal Agreement which covers separation issues such as:

  • market access for goods
  • ongoing customs
  • VAT and excise matters
  • intellectual property
  • ongoing police and judicial co-operation in both criminal and civil/commercial matters
  • the protection of data obtained before the end of transition
  • ongoing public procurement procedures
  • Euratom issues
  • ongoing EU judicial/administrative processes, and
  • privileges and immunities

Any regulations made under that power are subject to parliamentary scrutiny using the affirmative resolution procedure where they amend, repeal or revoke primary legislation or an EU regulation that was not tertiary legislation.

Notable points from a public law perspective

There is no doubt that the EU(W)A 2018 and the EU(WA)A 2020 will come to be recognised by the courts as constitutional statutes and it is clear that UK lawyers will be dealing with law originating in the EU for a long time to come no matter what type of future relationship is agreed between the UK and the EU.

It will take some time to fully appreciate the effects that leaving the EU has on UK law and its political and constitutional arrangements. However, at this stage four broad areas can be flagged.


Firstly, the legal framework established by the EU(W)A 2018 and EU(WA)A 2020 has the potential to be very complex. Two new categories of law are established (relevant separation agreement law and retained EU law), and it will require some digging on the part of practitioners to assess exactly what these new categories encompass.

Further complexity has been introduced by the way in which amendments to retained EU law have been developed. Many statutory instruments were first made in 2019 before the Withdrawal Agreement was signed in order to mitigate the risk that an agreement would not be reached. As such, these instruments did not include provision for a transition period or the Northern Ireland Protocol. There was therefore a flurry of legislative activity in late 2020 through which a swath of further statutory instruments were made to deal with these issues, including the fact that EU laws that became operative during the transition period now fall within the definition of retained EU law.

Scrutiny of secondary legislation

Secondly, taken together, the EU(W)A 2018 and EU(WA)A 2020 grant a great number of powers to the government to legislate using secondary legislation. Although the powers to amend retained EU law are subject to sifting by Parliamentary committees, some of the powers granted by the EU(WA)A 2020 are not. They also allow for regulations containing certain provisions to be subject only to scrutiny using the negative procedure in circumstances that were not permitted under the EU(W)A 2018 as enacted. Such circumstances include the creating or widening the scope of a criminal offence and increasing fees or taxes.

The sifting committees struggled with the volume of secondary legislation that they were required to consider in the 2017–2019 Parliament. It is also relatively certain that the government will seek to include further extensive powers to make delegated legislation in future Brexit-related primary legislation. It is not feasible that the sifting committees in their current form could adequately consider all Brexit-related regulations put forward by the government under the negative procedure to ascertain whether a higher degree of scrutiny is warranted.

This means that a vast amount of important legislation has been made with relatively little oversight. Some of it will be controversial and some of it will have errors. All of it will be susceptible to judicial review (within applicable time limits) in a way that primary legislation is not.

The role of the courts

Thirdly, prior to the EU(WA)A 2020, the EU(W)A 2018 had established a relatively clear position with respect to the way in which the decisions of EU courts were to be applied by UK judges. The water has been muddied, however, by Ministers granting lower courts the power to depart from EU case law that they would otherwise have had to apply.

This has the potential to damage legal certainty and to increase litigation as claimants seek to persuade UK courts to depart from certain aspects of EU law. It remains to be seen how judges will seek to use that power. It may be that judges in lower courts shy away from changes to retained EU case law even where they are given the power to do so.


Finally, it should be noted that both the devolved Parliaments in Scotland and Wales declined to provide legislative consent for the EU(WA)A 2020. Although this did not stop the legislation making it onto the statute book, it does illustrate that the devolved legislatures may have a different approach to legislating for the UK's withdrawal from the UK than does Westminster.

Given that the devolved authorities have parallel regulation-making powers to those given to UK Ministers under EU(W)A 2018, there may be some friction in how those powers are used in different parts of the UK, or by UK Ministers legislating for a devolved region, where the matter concerned is within devolved competence.

This may be particularly acute in Northern Ireland, given the difference in treatment of that jurisdiction under the Protocol on Ireland/Northern Ireland, together with the requirement for the Northern Ireland Assembly to periodically consent to the continuation of those arrangements. For further reading, see our insight Introduction to the Withdrawal Agreement.

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