Learning Outcomes
After reading this article, you will be able to identify and explain the main legal and practical limitations on the sovereignty of the UK Parliament. You will understand how EU law (including retained EU law), the Human Rights Act 1998, devolution, and judicial principles affect Parliament’s legislative supremacy. You will be able to apply these concepts to SQE1-style problem questions and scenarios.
SQE1 Syllabus
For SQE1, you are required to understand the doctrine of parliamentary sovereignty and the main limitations on Parliament’s legislative supremacy. Focus your revision on:
- the definition and core features of parliamentary sovereignty
- how EU law (including retained EU law) limits or limited Parliament’s powers
- the effect of the Human Rights Act 1998 and declarations of incompatibility
- the legal and political impact of devolution on Parliament’s competence
- the role of the courts and the rule of law as potential constraints on Parliament
- the practical significance of international law and constitutional statutes
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.
- What is the doctrine of parliamentary sovereignty, and what are its three core elements?
- How did EU law limit the sovereignty of Parliament before and after Brexit?
- What is the effect of a declaration of incompatibility under the Human Rights Act 1998?
- Can the UK Parliament legislate on devolved matters without the consent of devolved legislatures?
- In what circumstances have judges suggested that there may be limits to parliamentary sovereignty?
Introduction
The doctrine of parliamentary sovereignty is a central principle of the UK constitution. It means that Parliament can make or unmake any law, and no other body can override or set aside its legislation. However, in practice, Parliament’s legislative supremacy is subject to important legal and political limitations. These include the legacy of EU law, the Human Rights Act 1998, devolution, and the courts’ recognition of constitutional principles. Understanding these constraints is essential for SQE1.
The Doctrine of Parliamentary Sovereignty
Parliamentary sovereignty, as classically defined by A.V. Dicey, means that Parliament has the right to make or repeal any law, cannot bind its successors, and no person or body can override or question the validity of its legislation.
Key Term: parliamentary sovereignty The principle that Parliament has supreme legal authority to make or repeal any law, cannot bind future Parliaments, and its Acts cannot be set aside by any other body.
Key Term: constitutional statute A statute of fundamental constitutional importance, such as the Human Rights Act 1998 or the Scotland Act 1998, which courts may treat as immune from implied repeal.
Legal and Practical Limitations on Parliamentary Sovereignty
Despite its theoretical supremacy, Parliament’s power is limited in several ways. These limits are legal, political, and practical.
EU Law and Retained EU Law
Before Brexit
During the UK’s membership of the European Union, EU law had supremacy over domestic law in areas of EU competence. This was achieved through the European Communities Act 1972, which required UK courts to give effect to directly effective EU law, even if it conflicted with an Act of Parliament.
Key Term: supremacy of EU law The principle that EU law prevails over conflicting national law in areas of EU competence.
Factortame and Parliamentary Sovereignty
In R v Secretary of State for Transport, ex parte Factortame Ltd (No 2) [1991], the House of Lords accepted that it could disapply an Act of Parliament that conflicted with EU law. This marked a practical limitation on Parliament’s sovereignty in EU matters.
After Brexit
The European Union (Withdrawal) Act 2018 repealed the European Communities Act 1972 but converted a large body of EU law into domestic law as "retained EU law." Retained EU law continues to have a limited form of supremacy over pre-Brexit UK legislation, and the Withdrawal Agreement gives direct effect to certain EU rights, especially in relation to Northern Ireland.
Key Term: retained EU law EU law that was preserved in UK law after Brexit, continuing to apply unless and until amended or repealed by Parliament.
The Human Rights Act 1998
The Human Rights Act 1998 (HRA) incorporates the European Convention on Human Rights (ECHR) into UK law. Courts must interpret legislation, as far as possible, to be compatible with Convention rights (section 3 HRA). If this is not possible, higher courts may issue a declaration of incompatibility (section 4 HRA).
Key Term: declaration of incompatibility A formal statement by a higher court that a statute is incompatible with the ECHR, which does not invalidate the statute but signals to Parliament that amendment is needed.
A declaration of incompatibility does not invalidate the legislation, but it creates political pressure for Parliament to amend the law. The courts cannot strike down primary legislation for incompatibility with human rights.
Devolution
Devolution has created legislatures in Scotland, Wales, and Northern Ireland with power to legislate on devolved matters. However, the UK Parliament remains legally sovereign and can legislate on any matter, including devolved areas. The Sewel Convention states that the UK Parliament will not "normally" legislate on devolved matters without the consent of the devolved legislature, but this is a political, not a legal, constraint.
Key Term: Sewel Convention The constitutional convention that the UK Parliament will not normally legislate on devolved matters without the consent of the relevant devolved legislature.
International Law
The UK is a dualist state, so international treaties do not become part of domestic law unless incorporated by statute. However, courts may interpret domestic law to be consistent with international obligations where possible, and Parliament is often politically constrained by international agreements.
The Role of the Courts and the Rule of Law
In recent years, judges have suggested that there may be fundamental constitutional principles, such as the rule of law, that Parliament cannot override. In R (Jackson) v Attorney General [2005], some Law Lords indicated that the courts might refuse to give effect to extreme legislation that undermines the rule of law or basic constitutional values.
Key Term: rule of law The principle that all persons and authorities, including Parliament, are subject to and accountable under the law.
Key Term: judicial review The process by which courts supervise the legality of actions or decisions by public bodies, including the exercise of statutory and prerogative powers.
Express and Implied Repeal
Parliament cannot bind its successors, so any Act can be repealed expressly or by implication. However, courts have suggested that constitutional statutes cannot be repealed by implication—only by express words.
Worked Example 1.1
A new Act of Parliament is passed that conflicts with an earlier constitutional statute, but does not mention it. Is the earlier Act still in force?
Answer: Courts may treat the earlier constitutional statute as immune from implied repeal. Only express words in the new Act will repeal it.
Political and Practical Constraints
Even where Parliament has legal power, political realities may limit its actions. For example, Parliament is unlikely to repeal devolution statutes or the Human Rights Act due to political consequences, even though it has the legal authority to do so.
Worked Example 1.2
Parliament passes an Act that breaches an international treaty. What is the effect in UK law?
Answer: The Act is valid in domestic law, but the UK may face international consequences. Courts may interpret the Act to be consistent with the treaty if possible, but cannot set it aside solely for breach of international law.
The "Manner and Form" Debate
Some have argued that Parliament could require special procedures (such as a referendum or supermajority) to amend certain statutes. However, the orthodox view is that Parliament cannot bind its successors as to the manner or form of future legislation.
Judicial Warnings and the Rule of Law
While Parliament is legally supreme, some judges have warned that the courts might refuse to give effect to legislation that abolishes judicial review or undermines democracy. This remains a theoretical, not a practical, limit.
Exam Warning
The courts have never struck down an Act of Parliament for violating constitutional principles. However, you may be asked in the SQE1 about judicial statements suggesting possible limits to sovereignty in extreme cases.
Key Point Checklist
This article has covered the following key knowledge points:
- Parliamentary sovereignty means Parliament can make or repeal any law, cannot bind future Parliaments, and its Acts cannot be set aside by other bodies.
- EU law limited Parliament’s sovereignty during UK membership; retained EU law and the Withdrawal Agreement continue to constrain Parliament in some areas.
- The Human Rights Act 1998 requires courts to interpret legislation compatibly with the ECHR where possible, but does not allow courts to strike down primary legislation.
- Devolution gives legislative power to devolved legislatures, but the UK Parliament remains legally sovereign; the Sewel Convention is a political, not legal, constraint.
- International law does not override Acts of Parliament, but courts may interpret statutes to be consistent with international obligations.
- Courts have suggested that constitutional statutes cannot be repealed by implication, only by express words.
- Some judges have indicated that the rule of law may impose ultimate limits on Parliament, but this has not been tested in practice.
Key Terms and Concepts
- parliamentary sovereignty
- constitutional statute
- supremacy of EU law
- retained EU law
- declaration of incompatibility
- Sewel Convention
- rule of law
- judicial review
