Sources of English law

This note explores the principal sources from which English law derives its authority and content. While some legal systems are codified in a single comprehensive document, the English legal system is characterised by legal pluralism: its norms derive from legislation (primary and secondary), the common law developed through judicial precedent, principles of equity, retained EU law (until its recent sunset), and—marginally—certain customary and prerogative sources.

The concept of 'source' bears two meanings in this context. First, a formal source refers to the process or authority by which a rule acquires legal force (e.g., enactment by Parliament; binding judicial decision). Second, a material source identifies the substantive origin or inspiration of a rule (e.g., social policy; moral principle). This note is primarily concerned with formal sources, though their interaction with material considerations emerges in questions of statutory interpretation and judicial law-making.

Three themes recur throughout the topic:

• Hierarchy: Acts of Parliament are supreme; subordinate legislation and judicial decisions occupy lower tiers, subject to statutory override.
• Interaction: Legislation often codifies, modifies, or abolishes common law and equitable rules; courts interpret and apply statutes while developing interstitial principles.
• Institutional competence: Which institution—Parliament, the judiciary, the executive—is best placed to generate particular kinds of legal norm? This question underlies debates about judicial activism, delegated legislation, and the constitutional separation of powers.

Mastery of this topic is foundational: every substantive area of law you encounter this term—tort, contract, criminal law—depends on knowing which source supplies the operative rule and how that source is to be interpreted and applied.

The historical evolution of English legal sources reflects successive waves of institutional consolidation and ideological change.

The medieval common law

From the twelfth century, royal judges sitting in Westminster and on circuit began to articulate a body of rules applicable throughout the realm, distinguishing 'common' law from local custom and feudal jurisdiction. Decisions were recorded in Year Books, and the doctrine of precedent—though not yet rigorous—began to emerge. The common law courts (King's Bench, Common Pleas, Exchequer) developed distinct procedural writs, and substantive rights turned on the availability of a suitable form of action.

Equity and the Court of Chancery

By the fifteenth century, the common law's procedural rigidity and limited remedies prompted litigants to petition the Crown for discretionary relief. The Lord Chancellor, exercising the Crown's residual jurisdiction, developed a rival body of principles: equity. Equity supplied remedies (injunctions, specific performance) unavailable at common law and tempered strict legal rules with doctrines such as estoppel and the constructive trust. Conflict between the two systems was resolved in the Earl of Oxford's Case (1615) 1 Ch Rep 1, affirming equity's supremacy where the two conflicted. The Judicature Acts 1873–75 fused the administration of law and equity into a single Supreme Court of Judicature, though the substantive principles remain distinct.

Parliamentary sovereignty and the rise of statute

The Glorious Revolution of 1688 and the Bill of Rights 1689 entrenched the principle that Acts of Parliament constitute the supreme form of law, immune from judicial override. While statute law was historically piecemeal, the nineteenth and twentieth centuries witnessed increasing legislative intervention across tort, contract, property, and criminal law. The growth of the regulatory state, particularly after 1945, accelerated the production of delegated (or subordinate) legislation under statutory authority.

European Union law (1973–2020)

The European Communities Act 1972 gave effect to EU law in domestic courts and, by implication, constrained parliamentary sovereignty: domestic statutes had to be interpreted consistently with EU law, and directly effective EU provisions took precedence. The European Union (Withdrawal) Act 2018 and the European Union (Withdrawal Agreement) Act 2020 formally ended this supremacy, though significant volumes of retained EU law persisted until the Retained EU Law (Revocation and Reform) Act 2023 ('REUL Act 2023') introduced a sunset mechanism and assimilation framework.

Human Rights Act 1998

By requiring courts to interpret legislation compatibly with Convention rights 'so far as it is possible to do so' (s 3) and empowering senior courts to issue declarations of incompatibility (s 4), the Human Rights Act 1998 introduced a novel interplay between statute and judicial interpretation, without formally displacing parliamentary sovereignty.

Parliamentary sovereignty

Parliament can make or unmake any law, and no person or body may override or set aside an Act of Parliament. This doctrine, classically expounded by Dicey, underpins the hierarchy of sources: statute prevails over common law, equity, and (now) retained EU law. Post-Miller (No 1) [2017] UKSC 5, the Supreme Court confirmed that withdrawal from the EU required statutory authorisation; prerogative power could not alter domestic law. Parliamentary sovereignty remains the 'fundamental principle' of the constitution.

Judicial precedent and the doctrine of stare decisis

Courts are bound by decisions of higher courts in the same hierarchy. The ratio decidendi (the legal principle necessary to the decision) is binding; obiter dicta are persuasive only. The Supreme Court may depart from its own previous decisions when it appears right to do so (Practice Statement [1966] 1 WLR 1234). The Court of Appeal (Civil Division) is bound by its own decisions subject to narrow exceptions in Young v Bristol Aeroplane Co Ltd [1944] KB 718. This doctrine promotes consistency, predictability, and the rule-of-law value that like cases be treated alike.

The rule against judicial legislation

Foundation

1. What is the difference between primary and secondary legislation? Illustrate with examples and explain the legal consequences of the distinction.

1. Explain the doctrine of precedent. Why are courts bound by some decisions but not others?

Standard

1. 'The Human Rights Act 1998 requires courts to perform an interpretive gymnastics that respects parliamentary sovereignty while protecting fundamental rights.' Discuss with reference to ss 3 and 4 HRA 1998 and relevant case law.

1. To what extent can delegated legislation be challenged in the courts? Assess the constitutional justifications for, and limits on, judicial review of secondary legislation.

Challenge

1. 'Parliamentary sovereignty is a common law principle, not a political fact. It follows that the courts, which recognise it, may also qualify or withdraw that recognition.' Critically evaluate this claim in light of Jackson, Privacy International, and academic commentary.

Essential

• A.W. Bradley, K.D. Ewing, and C.J.S. Knight, Constitutional and Administrative Law (17th edn, Pearson 2018) chs 3–5 (parliamentary sovereignty, legislation, common law).
• R. Cross and J.W. Harris, Precedent in English Law (4th edn, Clarendon Press 1991) chs 1–3 (doctrine of precedent).
• F.A.R. Bennion, Bennion on Statutory Interpretation (8th edn, LexisNexis 2020) Parts II–III (principles of interpretation).

Academic commentary

• T.R.S. Allan, 'The Sovereignty of Law: Freedom, Constitution, and Common Law' (2013) 33 OJLS 487 (common law constitutionalism).
• Paul Craig, 'Constitutionalising Constitutional Law: HS2' [2014] Public Law 373 (sovereignty and judicial review).
• Aileen Kavanagh, 'The Elusive Divide Between Interpretation and Legislation under the Human Rights Act 1998' (2004) 24 OJLS 259 (s 3 HRA).

Primary sources

• Practice Statement (Judicial Precedent) [1966] 1 WLR 1234.
• Human Rights Act 1998, ss 2–4, 6.
• European Union (Withdrawal) Act 2018; Retained EU Law (Revocation and Reform) Act 2023.

Advanced

• Jeffrey Goldsworthy, The Sovereignty of Parliament: History and Philosophy (Clarendon Press 1999) (historical and theoretical foundations).
• N.W. Barber, 'The Afterlife of Parliamentary Sovereignty' (2011) 9 International Journal of Constitutional Law 144 (evolution of doctrine post-HRA and EU membership).