Retained EU law and the UK constitution - Modification and w...

Learning Outcomes

This article examines modification and withdrawal of retained EU law within the UK constitutional framework, including:

• Categories, preservation, and amendment of retained EU law in domestic legislation
• Parliamentary sovereignty and its relationship to the legislative process
• Legal mechanisms for alteration or repeal by Parliament and government ministers
• Primary versus secondary legislation as tools for change
• Henry VIII powers, their significance, and restraints
• Parliamentary scrutiny procedures and special procedures for constitutional or fundamental statutes
• Doctrines of direct effect, supremacy, and indirect effect as they relate to retained EU law
• Status and binding force of EU case law in UK courts post-withdrawal
• Judicial interpretation of retained EU law and compatibility with subsequently enacted domestic law
• Constitutional implications of the EU (Withdrawal) Act 2018 and subsequent enactments
• Practical issues involving the amendment or withdrawal of retained EU law
• Roles and limits of Parliament, government ministers, devolved institutions, and the courts

SQE1 Syllabus

For SQE1, you are required to understand the modification and withdrawal of retained EU law within the UK constitutional framework, with a focus on the following syllabus points:

• the definition and categories of retained EU law as preserved after Brexit
• mechanisms by which retained EU law may be amended, repealed, or replaced (including by Parliament and ministers under statutory powers)
• the legal basis and procedures for secondary legislation, including Henry VIII powers, and their controls/limitations
• the relationship between parliamentary sovereignty, the principle of legality, and modification of retained EU law
• the interpretation of retained EU law, status of pre-Brexit and post-Brexit CJEU case law, and the role of UK courts
• differences in status and modification of primary versus secondary retained EU legislation
• specific procedures for scrutinising changes to retained EU law
• the application of the rule of law, proportionality, and fundamental rights in relation to the withdrawal or alteration of retained EU law
• the constitutional status and practical implications of the EU (Withdrawal) Act 2018 and subsequent enactments

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.

1. What are the main categories of retained EU law in the UK legal system?
2. How can ministers modify retained EU law using secondary legislation, and what are the main limitations on this power?
3. Can Parliament repeal or amend retained EU law by passing a new Act? Why or why not?
4. How do UK courts treat pre-Brexit CJEU case law when interpreting retained EU law?

Introduction

The UK's withdrawal from the European Union required the creation of a legal mechanism to avoid sudden legal vacuums and ensure continuity and certainty in the domestic legal system. The European Union (Withdrawal) Act 2018 (EUWA 2018) provided the essential framework by preserving in UK law a wide body of previously applicable EU law—coined "retained EU law." This article analyses the legal architecture allowing the modification and withdrawal of retained EU law, how the UK’s constitutional principles such as parliamentary sovereignty and the rule of law frame these processes, and the institutional roles of Parliament, government ministers, the devolved administrations, and the judiciary.

Retained EU law plays an important role by providing stability in rights and obligations for individuals, businesses, government bodies, and courts. However, as UK law changes and diverges from the EU, and as the UK seeks to reform retained EU law in line with national priorities, clear legal mechanisms—together with constitutional safeguards—have become all the more important.

Key Term: retained EU law
Retained EU law is the body of rules and rights derived from the EU that were preserved in UK domestic law following Brexit. It comprises a range of legal sources, including enacted UK legislation implementing EU obligations, directly applicable EU legislation (such as regulations), and certain directly effective rights from EU treaties and case law.

Categories of Retained EU Law

Retained EU law is not a single homogeneous category, but rather a set of distinct legal sources with differing status and rules for modification or withdrawal. Under the EUWA 2018, these categories include:

• EU-derived domestic legislation: This is UK primary or secondary legislation (such as Acts of Parliament or statutory instruments) created to fulfil EU obligations—primarily laws made under s.2(2) of the European Communities Act 1972. This category also covers UK legislation passed to implement directives.
• Direct EU legislation: These are regulations, decisions, or tertiary legislation that were directly applicable in the UK immediately before Brexit. Such legislation is now retained EU law unless expressly excluded or repealed.
• Retained directly effective rights: Certain rights, powers, liabilities, obligations, and procedures recognised as directly effective in UK or EU courts before Brexit are also preserved as retained EU law. These can include directly effective treaty provisions and provisions of EU directives, but only where these were recognised before the end of the implementation period.

The status of retained EU law depends on its origin. For instance, retained direct principal EU legislation (such as EU regulations) is treated as equivalent to primary legislation for some purposes, while retained direct minor EU legislation (such as certain implementing or tertiary acts) is treated as secondary legislation. This categorisation determines, among other things, how retained EU law may be amended, the avenues for legal challenge, and the degree of parliamentary supervision required for any changes.

Key Term: direct effect
Direct effect refers to the characteristic of some EU law provisions being enforceable by, and against, individuals and the State in national courts without the need for domestic implementing measures.

Key Term: supremacy
Supremacy describes the principle that, while retained, EU law trumped conflicting national law—though since Brexit this principle only applies in certain circumstances.

Mechanisms for Modification and Withdrawal

The modification and withdrawal of retained EU law is governed by several core legal and constitutional principles. The principal mechanisms can be summarised as follows:

Parliamentary Powers

Parliament remains the ultimate legal authority for enacting, amending, or repealing any form of law in the UK legal system, including retained EU law. This flows from the doctrine of parliamentary sovereignty, whereby no person or body may set aside or override an Act of Parliament. Parliament can therefore:

• amend or repeal any retained EU law, whether it is an Act, statutory instrument, or other form (except where limits exist due to constitutional conventions or international law obligations)
• pass new primary legislation to replace entire frameworks previously based in EU law
• alter the status and effect of retained EU law, or even remove specific references to retained EU law going forward

This power is theoretically unlimited, but is affected in practice by constitutional conventions (such as the Sewel Convention in the context of devolution), international obligations, and principles of the rule of law and legality.

Key Term: parliamentary sovereignty
Parliamentary sovereignty means that Parliament is the supreme law-maker. No other institution, including the courts, ministers, or devolved legislatures, can override or set aside the laws it enacts.

Ministerial Powers and Secondary Legislation

One of the central features of the EUWA 2018 is the conferral of temporary but significant powers on ministers to amend retained EU law by statutory instrument. These are needed because many retained EU laws refer to EU institutions, reciprocal arrangements, or otherwise require amendment to function effectively post-Brexit.

Section 8 of the EUWA 2018—titled "dealing with deficiencies arising from withdrawal"—is key here. It grants ministers powers commonly called "Henry VIII powers" (after historical legislation conferring similar powers), to amend or repeal both primary and secondary retained EU law. The power exists to ensure continuity by correcting "deficiencies" in retained EU law, such as:

• obsolete references to 'EU institutions', 'Member States', or provisions concerning reciprocal rights
• provisions which require action by, or cooperation with, the EU or its agencies, which is no longer possible
• arrangements no longer workable or meaningful outside the EU

Actions under s.8 are subject to strict limitations and cannot be used to:

• introduce new taxes
• make retrospective legislative changes
• create a new public authority that did not previously exist in connection with the relevant function
• amend or repeal the Human Rights Act 1998
• create new criminal offences beyond specified limits

These powers are limited by a "sunset clause," originally expiring two years after the end of the Brexit implementation period, and by the requirement that secondary legislation making substantive changes is generally subject to the affirmative resolution procedure (i.e., requires positive approval from Parliament), while less substantial or technical changes may use the negative resolution procedure.

Key Term: Henry VIII powers
Henry VIII powers allow ministers to amend, repeal, or replace primary legislation (Acts of Parliament) by means of secondary legislation (statutory instruments), rather than going through the full legislative process.

Key Term: secondary legislation
Secondary legislation (or delegated legislation) refers to laws made by ministers, government departments, or other authorities under powers delegated by an Act of Parliament.

Scrutiny and Procedures

The procedures for adopting secondary legislation to amend retained EU law are determined by the significance of the proposed change:

• The affirmative resolution procedure means that both Houses of Parliament must expressly approve the instrument. This procedure is generally required for significant amendments, such as those altering the substantive content of laws or transferring functions from EU institutions to UK authorities.
• The negative resolution procedure allows the instrument to become law unless either House objects within a specified period (usually 40 days). This is reserved for less significant, corrective, or technical amendments.

These procedures provide important parliamentary oversight and act as a check on the executive’s ability to make broad or fundamental changes without debate.

Delegated Legislation—Examples of Correction

Many examples have arisen of the need to update retained EU law to reflect new domestic realities. For instance, before Brexit, a regulation might have required UK authorities to submit regular reports to the European Commission—an obligation that no longer makes sense outside the EU. Through secondary legislation, ministers can remove or update such requirements, replacing references to EU agencies with appropriate UK bodies.

Devolved Administrations

The devolved legislatures may amend retained EU law within their devolved competence. However, the UK Parliament reserves the right to legislate for the whole of the UK (notwithstanding conventions such as the Sewel Convention, which have political, not legal, force). Regulations under the EUWA 2018 prevent the devolved legislatures from modifying retained direct principal EU legislation unless specific conditions are satisfied, reinforcing the principle that key legal changes must maintain uniform legal effect, especially in areas closely connected to national interests.

Repeal and Replacement by Primary Legislation

Where significant reform is required, it is expected that Parliament will use primary legislation rather than relying on ministerial 'deficiency-correcting' powers. For example, the creation of a new regulatory regime for a whole sector, such as fisheries or agriculture, requires full parliamentary debate and scrutiny.

One prominent case is the Fisheries Act 2020, which repealed the former EU rules and replaced them with a UK-specific regime governing the management and exploitation of UK waters.

Key Term: primary legislation
Primary legislation refers to Acts of Parliament, which are the highest form of law in the UK legal system and may only be amended or repealed by Parliament itself.

Constitutional Safeguards

Constitutional safeguards ensure that processes for modifying or withdrawing retained EU law do not erode core principles of the UK constitutional order.

Limits on Ministerial Powers

While ministers have the authority to correct deficiencies in retained EU law, the scope of these powers is strictly limited by the parent statute, the EUWA 2018, and the principles of legality, proportionality, and judicial review. For instance, any exercise of Henry VIII powers must be:

• for a permitted purpose, as set out in the enabling Act
• reasonable, proportionate, and no more than necessary to address the deficiency
• exercised so as not to infringe fundamental rights or established constitutional principles

If a minister exceeds these statutory powers, a legal challenge by way of judicial review is possible. The courts will scrutinise, for example, whether the regulation has exceeded its mandate (ultra vires), whether parliamentary procedures were properly followed, and whether the use of powers is otherwise lawful.

Parliamentary Sovereignty

The bedrock principle remains that Parliament—the sovereign legislature—may make any law, and repeal or modify any previous law, including retained EU law. No retained EU law has higher status than any Act of Parliament passed after Brexit. If Parliament wishes, it may amend or repeal retained EU law as easily as any other legislation, subject to political constraints and principles of legality and fairness. The practical effect is that Parliament controls the future of retained EU law and is not bound by pre-Brexit law except where it chooses to be.

The doctrine of implied repeal is qualified by the courts in the case of constitutional statutes (e.g., the Magna Carta, Bill of Rights 1689, Human Rights Act 1998, EUWA 2018 itself), which, as recognised by Laws LJ in Thoburn v Sunderland City Council [2002], can only be repealed by express words. This principle encourages clear and deliberate legislative change, rather than change by accident, especially in areas of constitutional importance.

The Rule of Law and the Principle of Legality

Another fundamental safeguard is the principle of legality, which requires ministers and regulators to act lawfully and not to infringe fundamental constitutional rights unless clearly and expressly authorised by Parliament. This principle forms part of the wider "rule of law" doctrine, which asserts that all persons (including government ministers) are subject to and bound by the law.

Parliament's legislative supremacy is therefore balanced by the requirement that modifications to law—especially in areas affecting fundamental rights or constitutional norms—must be clear, and the use of delegated powers must be justified, reasonable, and subject to oversight and challenge.

Judicial Interpretation

Section 6 of the EUWA 2018 provides that UK courts:

• are not bound by decisions of the CJEU or unmodified retained EU law after Brexit (except for pre-Brexit CJEU case law, which is binding on all lower courts except where the Supreme Court or Court of Appeal choose to depart)
• must interpret retained EU law in line with the retained case law and general principles of EU law, so far as these have not been modified or replaced

UK courts therefore apply the doctrine of precedent to pre-Brexit CJEU decisions on retained EU law, but they may, in exceptional cases, depart from such case law using the same test as for departing from their own previous decisions. Since regulatory and legal conditions change, this mechanism allows for change but in a controlled and predictable manner.

Key Term: CJEU case law
CJEU case law refers to judgments of the Court of Justice of the European Union interpreting EU law. As to retained EU law, UK courts remain bound by pre-Brexit CJEU decisions unless and until a higher court departs from them.

If a question of interpretation arises concerning an amended (i.e., "modified") piece of retained EU law, UK courts interpret it in accordance with the clear intention of the amendment and need not follow pre-Brexit CJEU case law if incompatible.

UK courts are also no longer able to make Article 267 TFEU references to the CJEU.

Worked Example 1.1

Worked Example 1.1

A minister wants to use secondary legislation to amend a retained EU regulation that refers to the European Commission. Can the minister use Henry VIII powers to remove this reference?

Answer:
Yes, if the reference is now inappropriate due to Brexit, the minister can use Henry VIII powers under section 8 of the EUWA 2018 to correct this deficiency, provided the change does not exceed the limits set by the Act. The minister must use the appropriate parliamentary procedure and ensure that the change is proportionate and no more than is necessary. If the regulation is considered "direct" EU law (i.e., principal retained law), the change must be made following the stricter procedure for amending such instruments.

Worked Example 1.2

Parliament wishes to repeal a retained EU regulation on environmental standards and replace it with a new UK-specific law. What process must be followed?

Answer:
Parliament must pass a new Act to repeal or replace the retained EU regulation. This follows the standard legislative process, requiring approval by both Houses and Royal Assent. A full debate ensures scrutiny, and the replacement Act may expressly disapply or modify the prior retained EU law, subject to the principle of legality and any applicable constitutional conventions (such as seeking the consent of devolved legislatures for devolved matters).

Worked Example 1.3

Can a devolved legislature unilaterally repeal or amend a piece of retained direct principal EU legislation within its region?

Answer:
Generally, no. The EUWA 2018 restricts devolved legislatures from amending retained direct principal EU legislation, except in specified circumstances and within their devolved competence. The UK Parliament retains the ultimate authority to legislate for all parts of the UK, but constitutional convention (e.g., the Sewel Convention) suggests it will not normally do so in devolved areas without consent.

Worked Example 1.4

A government minister uses the powers under s.8 EUWA 2018 to create a statutory instrument making retrospective changes to a retained EU regulation. Is this lawful?

Answer:
No. The statutory powers under s.8 EUWA 2018 do not permit ministers to make retrospective legislation when correcting deficiencies in retained EU law. Any such change would be ultra vires and susceptible to challenge by judicial review.

Exam Warning

The use of Henry VIII powers is controversial. For SQE1, remember that ministers cannot use these powers to make major policy changes or to amend the Human Rights Act 1998. Any significant reform of retained EU law requires a new Act of Parliament. Delegated legislation must stay within the scope defined by the enabling Act, and attempts to go beyond these limits may be struck down by the courts.

Revision Tip

In answering questions about modification or withdrawal of retained EU law, always identify the legal source (primary or secondary), the body making the change (Parliament, minister, devolved legislature), the nature and scope of the power relied upon, and whether the correct statutory procedures and constitutional safeguards have been followed.

Summary Table: Modification and Withdrawal of Retained EU Law

Key Point Checklist

This article has covered the following key knowledge points:

• Retained EU law is comprised of EU-derived UK legislation, direct EU legislation, and directly effective rights preserved in domestic law after Brexit.
• Modification or withdrawal of retained EU law may be effected by Parliament via the enactment of new primary legislation, with no law immune from amendment or repeal except in line with constitutional principles.
• Ministers may use Henry VIII powers under s.8 of the EUWA 2018, via secondary legislation, to correct Brexit-related deficiencies, but these powers are limited to specified purposes, are time-limited, and are subject to parliamentary scrutiny and judicial oversight.
• Any attempt by ministers to make retrospective changes or introduce new taxes under these powers is ultra vires and unlawful.
• Parliamentary sovereignty is undiminished—no retained EU law can override a new Act of Parliament passed after Brexit, but constitutional statutes may only be amended or repealed by express words.
• Judicial review provides a constitutional check on the exercise of delegated powers. Ministers must act reasonably, proportionately, and for a permitted purpose when modifying retained EU law.
• The devolved legislatures may amend certain retained EU laws, but their powers are constrained in respect of direct principal EU legislation.
• UK courts follow pre-Brexit CJEU case law when construing retained EU law unless a higher court chooses to depart; lower courts must do so unless otherwise directed.
• Post-Brexit decisions of the CJEU are of persuasive but not binding value, and UK courts have final interpretative authority.
• The principle of legality ensures that fundamental rights and constitutional principles are not overridden except by express and unambiguous statutory wording.

Key Terms and Concepts

• retained EU law
• parliamentary sovereignty
• Henry VIII powers
• secondary legislation
• direct effect
• supremacy
• primary legislation
• CJEU case law