Parliamentary Sovereignty — Dicey, Modern Limits, and the HRA

Parliamentary sovereignty is the foundation principle of UK constitutional law. Its classical statement comes from AV Dicey: Parliament can make or unmake any law, no Parliament can bind its successors, and no body has the authority to override or set aside an Act of Parliament.

1. Dicey’s three propositions.

• Unlimited legislative power: Parliament can legislate on any subject. The classical illustration: in Mortensen v Peters (1906) the Scottish High Court of Justiciary held it had no power to review the validity of an Act of Parliament.
• No Parliament can bind its successors: implied repeal — Vauxhall Estates v Liverpool Corporation [1932] 1 KB 733 and Ellen Street Estates v Minister of Health [1934] 1 KB 590 — holds that a later Act overrides an earlier inconsistent one, even if the earlier one purported to be unrepealable.
• No higher authority: no court can strike down an Act on substantive grounds. British Railways Board v Pickin [1974] AC 765 confirms that even the procedural validity of an Act is not justiciable.

2. Modern challenges.

EU law (pre-Brexit). R v Secretary of State for Transport, ex parte Factortame (No 2) [1991] 1 AC 603: UK courts disapplied an Act of Parliament for inconsistency with directly effective EU law. Some scholars treated this as fatal to Dicey; others as Parliament voluntarily accepting an external constraint via the European Communities Act 1972 and retaining the right to repeal it (which it eventually did, via the EU (Withdrawal) Act 2018).

Human Rights Act 1998. Section 3 obliges courts to read legislation compatibly with ECHR rights so far as possible. Section 4 lets courts issue a declaration of incompatibility — symbolically powerful, but formally non-binding. Parliament can still legislate contrary to Convention rights and the courts cannot strike down. Ghaidan v Godin-Mendoza [2004] UKHL 30; Bellinger v Bellinger [2003] UKHL 21.

Jackson v Attorney General [2005] UKHL 56. Lords Steyn and Hope (obiter) entertained the possibility that a court might refuse to recognise an Act seeking to abolish judicial review of executive action — that is, that there are common-law constitutional fundamentals beyond Parliament’s unrestricted reach. Strictly obiter; never tested.

Constitutional statutes. Thoburn v Sunderland City Council [2002] EWHC 195 (Admin) (the “Metric Martyrs” case): Laws LJ identified a class of “constitutional statutes” (Magna Carta, Bill of Rights 1689, ECA 1972, HRA 1998) that cannot be impliedly repealed — only expressly. A modest doctrinal carve-out from full implied repeal.

3. Contemporary view. The orthodox position survives: Parliament remains sovereign as a matter of UK domestic law. The HRA, devolution settlements, and the EU Withdrawal regime all operate as Parliament-imposed self-restraints rather than external limitations. Whether those self-restraints amount to a substantive shift in the rule of recognition (HLA Hart’s phrase) is a live jurisprudence-of-public-law question.

Exam approach. State Dicey. Identify the modern challenge in the question. Apply the case authority. Discuss whether the challenge is a dilution of sovereignty in fact, or merely a Parliamentary self-restraint that retains the orthodox doctrine.

See also our judicial review guide and the glossary for ultra vires, locus standi, and Wednesbury.