Parliamentary sovereignty — Dicey and its critics

Parliamentary sovereignty is the foundational principle of the modern UK constitution and the most contested doctrine in contemporary public law. The orthodox account is Dicey''s: Parliament can make or unmake any law, no Parliament can bind its successors, and no body other than Parliament has the right to override or set aside its legislation. Each of these three propositions has attracted serious criticism, and each is now qualified in ways that Dicey did not anticipate.

This week explores Dicey''s account, the principal critical responses, and the modern case-law that has tested both. The doctrinal payoff is the ability to identify, when reading any constitutional case, which version of sovereignty the court is operating with — Dicey''s, the manner-and-form alternative, or some hybrid.

The topic connects to W1 (the sources of the constitution), W3 (the rule of law — competing foundational principle), W4 (separation of powers), W7 (EU law and Brexit — the Factortame and Miller I cases), and W8 (HRA — the Ghaidan and Bellinger line on s 3). It is also the conceptual foundation for the FHS-year material on prerogative, devolution, and the constitutional dialogue between Parliament and the courts.

Dicey''s account in An Introduction to the Study of the Law of the Constitution (1885) was the first systematic statement of parliamentary sovereignty as a legal doctrine. Dicey worked from the historical experience of seventeenth- and eighteenth-century constitutional struggles — the Case of Proclamations (1611), the Petition of Right 1628, the Civil War, the Glorious Revolution of 1688, the Bill of Rights 1689, and the Acts of Union 1706–07 — and abstracted from those events a settled doctrine that Parliament was the supreme law-making authority.

The nineteenth-century context shaped the doctrine in three ways. First, Dicey was writing in the high-Victorian period of parliamentary government — when the practical sovereignty of the legislature was the dominant political fact. Secondly, he was writing in opposition to the theoretical possibility of judicial review of statutes that had been canvassed by writers like Coke (Bonham''s Case 1610: ''when an act of parliament is against common right or reason ... the common law will controul it''). Thirdly, he was responding to American constitutionalism, where the written-constitution model with judicial review of statutes was developed in Marbury v Madison 5 US 137 (1803). Dicey wanted to assert that the British model was different in kind, not merely in degree.

The twentieth century tested Dicey''s account against new pressures: the rise of the welfare state and the concomitant growth in administrative law (Wade); the post-war international human-rights regime (the ECHR 1950); the European Communities Act 1972 and EU membership; devolution; the Human Rights Act 1998. Each pressure produced doctrinal innovation and academic critique. The post-Brexit settlement has not removed the pressures: the HRA and devolution continue to test sovereignty, and the Miller cases have given the modern doctrinal frame.

Dicey''s account has three propositions.

(1) Parliament can make or unmake any law. This is the positive limb. There is no subject-matter limit on Parliament''s legislative authority. Parliament may legislate on any topic, however absurd or oppressive, and the courts will give effect to its enactments. Dicey''s example was that Parliament could lawfully provide that all blue-eyed babies be killed. The proposition is normative as well as descriptive: Parliament is sovereign, and the doctrine asserts that this is the proper foundation of the legal order.

Five graded practice questions are provided in the panel below — two foundation questions on Dicey''s three propositions and the manner-and-form alternative, two standard questions on Thoburn and the Jackson dicta, and one challenge question on the rule of recognition.

See the Further Reading panel for Dicey, Jennings, Wade, Goldsworthy, Allan, the Hart-Allan tradition, and the post-Miller II commentary.