Learning Outcomes
This article outlines the categories, status, and interpretation of retained EU law in the UK constitution, including:
- Categories of retained EU law under the European Union (Withdrawal) Act 2018, including distinctions between EU-derived domestic legislation, retained direct EU legislation, and directly effective rights under s 2(1) ECA 1972
- Pre-Brexit EU law with continuing legal force in the UK and the significance of these categories
- Legal status of retained EU law within the UK hierarchy and its interaction with domestic legislation, including the effect of post-Brexit amendments
- Parliamentary sovereignty in conjunction with retained EU law and practical consequences, including legislative supremacy and possible derogations
- Principles guiding the interpretation of retained EU law, including the continued effect of pre-Brexit CJEU case law and general principles of EU law
- Circumstances in which UK courts may consider or depart from retained EU case law and the powers and limitations of different courts
- Doctrines relevant to retained EU law, including supremacy, direct effect, and indirect effect
- Legislative process and constitutional context for creating retained EU law, including correcting deficiencies and delegated powers to ministers and devolved administrations
- Continuing relevance of EU-derived rights and boundaries of parliamentary autonomy under the reformed UK constitutional structure
SQE1 Syllabus
For SQE1, you are required to understand retained EU law within the UK constitution, including its categories, legal status, and interpretation, with a focus on the following syllabus points:
- the categories and sources of retained EU law
- the legal status and hierarchy of retained EU law within the UK legal system
- the principles and methods used by UK courts to interpret retained EU law
- the relationship between retained EU law, domestic legislation, and parliamentary sovereignty
- the role of pre-Brexit CJEU case law and the ability of UK courts to depart from it
Test Your Knowledge
Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.
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Which of the following is NOT a category of retained EU law under the European Union (Withdrawal) Act 2018?
- EU-derived domestic legislation
- Direct EU legislation
- Rights arising under s 2(1) ECA 1972
- Post-Brexit EU regulations
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Which UK courts have the power to depart from retained EU case law?
- All UK courts
- Only the Supreme Court and Court of Appeal (or equivalent)
- Only the High Court
- Only the Supreme Court
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If a conflict arises between retained EU law and a UK Act of Parliament passed after 31 December 2020, which prevails?
- Retained EU law
- The later Act of Parliament
- Whichever was enacted first
- The CJEU decides
Introduction
The UK's withdrawal from the European Union marks a fundamental transformation in its constitutional arrangements. To preserve legal certainty and avoid gaps following Brexit, the European Union (Withdrawal) Act 2018 (EUWA) created the concept of retained EU law. This new legal category captures much of the body of EU law that applied in the UK on or before 31 December 2020, integrating it into the UK's legal system and thus ensuring continuity and stability.
Understanding the different categories, legal status, and mechanisms for the interpretation of retained EU law is important for functioning legal knowledge in constitutional law. This area directly engages with themes of the UK’s unwritten constitution, parliamentary sovereignty, statutory interpretation, and the evolving relationship between the UK’s domestic courts and the European legal order.
Categories of Retained EU Law
Retained EU law is not homogeneous; it comprises several distinct types of norms, all preserved or incorporated under EUWA to ensure the continuity of legal rights and obligations. Recognising the sources and nature of these categories is essential for determining how each operates within the UK's legal architecture post-Brexit.
EU-derived Domestic Legislation
EU-derived domestic legislation consists of UK laws (both primary and secondary) that were originally enacted to give effect to, or implement, obligations arising under the UK's membership of the EU.
Typical examples include:
- Statutory instruments made under section 2(2) of the European Communities Act 1972 (ECA 1972), which transposed directives into UK law, such as the Working Time Regulations 1998 (SI 1998/1833).
- Primary legislation that implements EU obligations, such as certain provisions of the Equality Act 2010 (which implements multiple EU equality directives).
This category covers all legislation that was operative and in force immediately before the end of the transition period. Critically, EUWA ensures that neither repeal of the ECA 1972 nor exit from the EU automatically repealed this body of law; it continues in force unless specifically amended or repealed by domestic legislation passed afterwards.
Key Term: EU-derived domestic legislation
UK statutes and statutory instruments made to implement EU law before Brexit, now preserved as part of retained EU law.
Direct EU Legislation
Direct EU legislation refers principally to EU Regulations and certain Decisions that, while the UK was a member, were directly applicable in domestic law without the need for further national implementing measures. These instruments, as a result, had immediate effect within the UK legal order.
The EUWA captures such legislation, ensuring that all directly applicable EU measures operative immediately before 31 December 2020—subject to certain exclusions and corrections—are converted into UK law as "retained direct EU legislation".
Direct EU legislation is further subdivided under the Act into:
- Retained direct principal EU legislation: generally, substantial Regulations of general application (for instance, the General Data Protection Regulation as it existed at the end of the transition period).
- Retained direct minor EU legislation: typically tertiary EU law (created under authority derived from principal EU legislation) and certain Decisions addressed to the UK.
The distinction is important for the purposes of amendment and challenge:
- Principal legislation is subject to amendment or repeal only by primary legislation or, in some exceptional cases, delegated legislation with special scrutiny.
- Minor direct legislation is treated as secondary legislation, so may be amended through the ordinary secondary legislative process.
Key Term: Direct EU legislation
EU regulations and decisions that applied directly in the UK before Brexit, now preserved as retained EU law.
Rights Arising Under Section 2(1) ECA 1972
Section 2(1) of the ECA 1972 allowed for directly effective EU rights—such as those flowing from EU Treaties or clear, unconditional provisions of directives—to be enforceable in UK courts. The Withdrawal Act preserves, as retained EU law, those rights, obligations, and remedies which were “recognised and available in domestic law” prior to exit day, but only if they had already been given effect by the UK courts or the CJEU.
A classic example is the right to equal pay between men and women under Article 157 of the Treaty on the Functioning of the European Union (TFEU), which could be invoked directly before national courts. Such directly effective Treaty rights will continue to be retained EU law for as long as they are not expressly repealed or amended by Parliament.
Importantly, only those rights which were already recognised as directly effective by UK or EU courts before 31 December 2020 are preserved. Rights not yet recognised, or which only arose under legislation coming into force after exit day, do not become retained EU law.
Key Term: Rights arising under s 2(1) ECA 1972
Directly effective EU treaty or directive rights recognised before Brexit, now preserved as retained EU law.
Retained EU Case Law and General Principles
In interpreting retained EU law, UK courts are required to continue having regard to the case law of the CJEU as it stood immediately before the end of the transition period, unless and until a higher UK court determines otherwise. This inherited case law—across areas from free movement, equality, procurement, and environmental law—remains central to the interpretation of retained EU law to preserve consistency and legal certainty.
"General principles of EU law", such as proportionality, legal certainty, equality, and procedural fairness, which were recognised by the CJEU before exit day, are also retained (though with important limitations) for the purposes of interpreting retained EU law.
Key Term: Retained EU case law
CJEU and UK court decisions on EU law made before Brexit, which remain binding for interpreting retained EU law.Key Term: General principles of EU law
Fundamental principles developed by the CJEU (e.g., proportionality, equality) that guide the interpretation of retained EU law if recognized before Brexit.
Exclusions from Retained EU Law
Certain aspects of EU law were not retained. Notably, the EU Charter of Fundamental Rights does not form part of retained EU law, though many of the substantive rights are preserved through domestic acts or general principles. Furthermore, any post-Brexit EU legislation or CJEU decisions issued after 31 December 2020 do not create retained EU law, though they may be treated by UK courts as persuasive (rather than binding) authorities.
Status of Retained EU Law
Retained EU law occupies a unique constitutional position as a hybrid creature of domestic law. Its status depends on its source, its place in the UK’s legislative hierarchy, and whether it has been amended since Brexit.
Legal Hierarchy and Supremacy
Retained EU law does not hold an absolute or entrenched constitutional status, but its location in the legal hierarchy is complex:
- Retained EU law generally prevails over pre-Brexit domestic Acts of Parliament and subordinate legislation if there is a conflict, reflecting the historic doctrine of EU supremacy during the period of UK membership. When interpreting ambiguous domestic law enacted before the end of 2020, courts should construe it, so far as possible, in a manner consistent with retained EU law.
- However, Acts of Parliament or statutory instruments enacted after 31 December 2020 take precedence over any contrary provisions of retained EU law, reaffirming the doctrine of parliamentary sovereignty. Parliament now has unfettered authority to amend or repeal retained EU law (subject only to some specific constraints in the context of the Northern Ireland Protocol and the post-Brexit agreements).
Key Term: Supremacy of retained EU law
The rule that retained EU law prevails over earlier UK law, but not over Acts of Parliament passed after Brexit.
Classification as Primary or Secondary Legislation
The status of a particular piece of retained EU law has practical ramifications for how it may be amended, repealed, or challenged by the courts:
- EU-derived domestic legislation retains its previous legal status (e.g., if originally enacted as primary legislation, it remains so; similarly for secondary legislation).
- Retained direct principal EU legislation is treated as akin to primary legislation, granting it a higher degree of legal protection and subject to challenge generally only by a declaration of incompatibility where relevant (such as under the Human Rights Act 1998).
- Retained direct minor EU legislation is generally treated as equivalent to secondary legislation.
The practical effect is that modifying or revoking retained direct principal EU legislation usually requires primary legislation (an Act of Parliament), whereas minor direct EU legislation can be amended or repealed through the usual secondary legislative process.
Amendment and Repeal
Parliamentary sovereignty means that both retained direct and EU-derived legislation can be amended, repealed, or replaced at will by the UK Parliament. In line with normal constitutional principles, Acts of Parliament will always prevail over earlier legislation, and retained EU law can be amended, replaced, or disapplied by new legislation as Parliament sees fit.
Where an area of retained EU law is devolved, the devolved legislatures (the Scottish Parliament, Senedd Cymru, and Northern Ireland Assembly) may also have the power to amend or repeal relevant retained EU law within their competence, except to the extent limited by Westminster.
Retained EU law also interacts with the devolution settlement: the UK Internal Market Act 2020 has further implications, preserving the coherence of economic arrangements across the UK and sometimes limiting devolved competence to prevent regulatory divergence.
Interaction with Domestic Law
Retained EU law must be interpreted in its original legal context. For any pre-2021 domestic laws intended to implement or complement EU law, the principle of conformity remains persuasive, but once Parliament exercises its legislative power, new domestic enactments will take precedence.
Where conflicts exist, UK courts must analyse:
- Whether the UK law in question is pre- or post-Brexit;
- The legal status of both the retained EU law and the domestic law (primary or secondary);
- Parliamentary intention behind subsequent enactments.
In such circumstances, the doctrine of implied repeal gives way to express provisions of the Withdrawal Act for that body of law. The doctrine of continued supremacy for pre-Brexit law is preserved for certainty, but all post-Brexit lawmaking is subject only to the UK’s own constitutional requirements.
Interpretation of Retained EU Law
The question of interpretation is significant. It determines how rules originating from an EU source are to be read and applied under domestic law, how much weight is given to historic EU case law, and the extent to which UK courts are bound to follow past CJEU precedents.
Statutory Interpretation: Key Principles
UK courts have adopted a purposive approach—the interpretive method most consistent with EU law—when reading retained EU law. The intention is to preserve, so far as possible, consistency with the EU law’s original purpose and objectives, and maintain legal certainty for those governed by it.
Key Term: purposive approach
A method of interpreting legislation by reference to the broader aims and objectives that led to its enactment, often looking beyond literal wording.
In practice, UK courts will:
- Approach retained EU law using the same purposive principles as would have been applied while the UK was an EU member.
- Continue to interpret relevant measures in accordance with pre-Brexit CJEU case law and general principles of EU law (if they remain part of retained law).
The Role of Pre-Brexit CJEU Decisions
A central pillar of EUWA is that pre-Brexit decisions of the CJEU are binding when UK courts interpret retained EU law, unless and until a higher UK court decides to depart from that case law. This ensures continuity and respects the expectation of legal actors relying on settled principles.
- All courts and tribunals below the Supreme Court and Court of Appeal (and other specified higher courts) remain bound by pre-Brexit (retained) EU case law regarding the interpretation of retained EU law.
- The Supreme Court (and, since late 2020, the Court of Appeal and equivalent higher courts) may depart from retained EU case law "when it appears right to do so," applying the same principles as when departing from their own previous decisions.
Where the relevant rules have not been modified substantively, UK courts are expected to apply the existing jurisprudence unless there is a strong justification for change to ensure legal certainty and continuity.
The Role of Post-Brexit CJEU Decisions
Decisions of the CJEU handed down after 31 December 2020 are not binding as a matter of UK law. However, UK courts may "have regard to" such decisions where they are relevant and may treat them as persuasive authority. Courts are not required to follow them, and should consider factors such as subsequent developments in UK statutory law, the coherence of UK legal principles, and the intention of Parliament.
This approach helps to strike a balance between maintaining a stable legal regime rooted in historic EU law and allowing for domestic development and the assertion of full legislative and judicial sovereignty post-Brexit.
Indirect Effect
In line with historic practice, UK courts may still interpret domestic law, including retained EU law, in a manner consistent with the aims and objectives of the relevant EU provision, known as the principle of indirect effect. This remains the case especially for those pieces of UK legislation that were originally passed to implement an EU obligation (e.g., transposing a Directive).
Indirect effect ensures that, so far as possible, domestic law and retained EU law are interpreted harmoniously, supporting legal certainty and minimising disruption. However, if the UK Parliament clearly legislates to the contrary, that intent will prevail.
Correcting Deficiencies
The EUWA also grants ministers (for a time-limited period) so-called "Henry VIII powers" to make consequential changes to retained EU law by secondary legislation. This includes powers to correct references to EU institutions, update terminology, or make other technical adjustments so that legal texts "work" in the UK context.
Key Term: Henry VIII powers
Legislative powers granted to ministers enabling them to amend or repeal primary legislation via secondary legislation under specified circumstances.
The powers are not unlimited. Ministers may not use them to make substantial policy changes without further parliamentary authorisation, to make retrospective laws, to increase taxes, or to create new criminal offences with significant penalties.
Once this period expires, such powers lapse, and future substantive changes to retained EU law require new Acts of Parliament or legislative measures with relevant authority.
Departing from Retained EU Case Law
Only the Supreme Court, the Court of Appeal and equivalent higher courts in England and Wales, Scotland, and Northern Ireland are authorised to depart from retained EU case law, and only when applying the same test as they would when departing from their own previous decisions (i.e., "when it appears right to do so"). This ensures a system of precedent and certainty for lower courts while empowering higher courts to respond to UK law if appropriate, in light of changing circumstances or a coherent domestic jurisprudence.
Lower courts remain bound by pre-Brexit CJEU decisions unless expressly overruled by a competent higher court.
General Principles of EU Law and the Charter
While many general principles of EU law (such as proportionality and equality) are retained for the interpretation of retained EU law, the EU Charter of Fundamental Rights was not incorporated into UK law by the EUWA. Thus, arguments based solely on Charter rights are not available before UK courts. However, general principles recognised in a pre-Brexit context can continue to inform interpretation, albeit with no independent right of action deriving solely from such principles.
Key Term: general principles of EU law
Broad legal principles developed by the CJEU to ensure consistent interpretation and protection of rights; only those recognised before Brexit are retained for interpreting retained EU law.
Worked Example 1.1
A UK court is asked to interpret a retained EU regulation on air passenger compensation. The regulation was directly applicable before Brexit, and the CJEU had decided before Brexit that compensation must be paid for certain delays. Can the UK court follow the CJEU's interpretation?
Answer:
Yes. The UK court must apply the pre-Brexit CJEU decision when interpreting the retained EU regulation, unless a higher UK court has decided to depart from it.
Worked Example 1.2
A conflict arises between a retained EU regulation and a UK Act of Parliament passed in 2022. Which law prevails?
Answer:
The UK Act of Parliament passed after 31 December 2020 prevails over retained EU law, reflecting parliamentary sovereignty.
Worked Example 1.3
Suppose a UK court of first instance is uncertain about the meaning of a provision in retained direct EU legislation. The provision has been clarified in a pre-Brexit CJEU judgment. However, there is some academic criticism of the CJEU's reasoning. What should the court do?
Answer:
The court should follow the pre-Brexit CJEU judgment, as it forms part of "retained EU case law." Academic criticism alone does not permit departure from binding precedents; only the Supreme Court, the Court of Appeal, or equivalent higher courts can decide to depart where justified.
Worked Example 1.4
A minister uses the powers under EUWA to correct a deficiency in a regulation on mutual recognition of professional qualifications. The amendment replaces all references from "Member State" to "United Kingdom" and omits joint enforcement duties with EU institutions. Has the minister acted within legal powers?
Answer:
Provided the amendments are necessary to ensure the regulation functions post-Brexit and do not go beyond correcting technical deficiencies (i.e., do not substantively change policy or create new taxes/offences), the minister has acted within the legal powers granted under the EUWA.
Exam Warning
For SQE1, remember that not all EU law is retained. Only EU law operative in the UK before the end of the transition period is preserved. Post-Brexit EU law, new CJEU decisions, and the EU Charter of Fundamental Rights are not part of retained EU law.
Summary
Retained EU law is a distinct category of UK law created to ensure legal continuity after Brexit. It includes EU-derived domestic legislation, retained direct EU legislation (such as Regulations), and certain directly effective rights previously conferred under section 2(1) ECA 1972. Retained EU law generally prevails over domestic law enacted before Brexit but not over new Acts of Parliament. UK courts must interpret retained EU law in line with pre-Brexit CJEU case law unless a higher court decides to depart from it. Ministers have time-limited powers to correct technical deficiencies in retained EU law, but substantive policy changes require new primary legislation. The EU Charter of Fundamental Rights and post-Brexit EU law are not part of retained EU law.
Key Point Checklist
This article has covered the following key knowledge points:
- Retained EU law consists of EU-derived domestic legislation, direct EU legislation, and certain directly effective rights recognised before exit day.
- Only EU law operative in the UK before 31 December 2020 is retained; later EU law, new CJEU case law, and the Charter of Fundamental Rights are excluded.
- Retained EU law holds a unique status: it prevails over domestic legislation enacted before Brexit, but yields to UK Acts of Parliament passed after 31 December 2020.
- The status of a retained EU law provision (as primary or secondary legislation) determines how it can be amended, repealed, or challenged.
- UK courts interpret retained EU law using a purposive approach consistent with the purpose and wording of the original EU provision.
- Pre-Brexit CJEU rulings and general principles recognised before exit day remain binding for interpreting retained EU law, unless a higher UK court departs from them.
- Only the Supreme Court, Court of Appeal, and equivalent appellate courts may depart from retained EU case law, and they do so using a test equivalent to departing from their own previous decisions.
- Ministers may make secondary legislation to correct technical or operational deficiencies in retained EU law, subject to limits and time restrictions.
- The EU Charter of Fundamental Rights and post-Brexit EU law are not part of retained EU law; general principles of EU law are retained only if recognised before exit day for interpreting, not as a source of new rights of action.
Key Terms and Concepts
- EU-derived domestic legislation
- Direct EU legislation
- Rights arising under s 2(1) ECA 1972
- Retained EU case law
- General principles of EU law
- Supremacy of retained EU law
- Purposive approach
- Henry VIII powers