Parliamentary sovereignty — Dicey and its critics

Parliamentary sovereignty comprises three Diceyan propositions: Parliament can make or unmake any law (positive limb); no Parliament can bind its successors (temporal limb); no body other than Parliament can override or set aside its legislation (exclusivity limb). The doctrine asserts that Parliament is the supreme law-making authority and courts must give effect to its enactments, however absurd or oppressive. This principle emerged from seventeenth- and eighteenth-century constitutional struggles and was systematised by Dicey as the foundation of the UK's legal order, distinguishing it from written-constitution models with judicial review of statutes.

Vauxhall Estates Ltd v Liverpool Corporation [1932] 1 KB 733; Ellen Street Estates v Minister of Health [1934] 1 KB 590: Parliament cannot entrench legislation against future repeal; later Acts prevail by implied repeal. Foundational for Dicey's second proposition.

Pickin v British Railways Board [1974] AC 765: Courts cannot investigate alleged procedural irregularities in enactment once an Act is on the statute roll. Establishes the enrolled bill rule.

R v Secretary of State for Transport, ex parte Factortame Ltd (No 2) [1991] 1 AC 603: UK statute disapplied for conflict with EU law — "the most significant qualification" of sovereignty (Lord Bridge). Qualification was conditional on the 1972 Act.

Thoburn v Sunderland City Council [2002] EWHC 195 (Admin): Constitutional statutes (Bill of Rights, Acts of Union, ECA 1972, HRA 1998) are not subject to implied repeal. Partial qualification of Dicey's temporal limb.

R (Jackson) v Attorney General [2005] UKHL 56: Dicta from Lord Steyn [102], Lord Hope [104]–[107], Baroness Hale [159] suggested rule-of-law limits on sovereignty. Influential but not followed as ratio.

Courts apply sovereignty through three analytical steps. First, identify whether the provision is in a duly enacted Act of Parliament (enrolled bill rule from Pickin). Second, determine if any qualification applies: is it a constitutional statute requiring express repeal (Thoburn)? Does the HRA s 3 interpretive obligation apply? Third, apply the statutory provision as Parliament intended, using orthodox interpretive techniques unless constitutional principles require strained reading (s 3 HRA). Common triggers include challenges to retrospective legislation, attempts to oust judicial review, conflicts between statutes (implied repeal analysis), and human rights incompatibilities. Courts preserve sovereignty's form while using interpretive techniques to minimise constitutional friction.

Students consistently make three errors. First, treating Factortame as abolishing sovereignty — it merely qualified it conditionally through the 1972 Act, now repealed. Second, citing Jackson dicta as binding law on rule-of-law limits — they remain influential dicta only, never adopted as ratio. Third, conflating sovereignty with absence of judicial review — sovereignty means courts cannot strike down primary legislation, not that they have no review jurisdiction over executive action or statutory interpretation.