Sources of law & doctrine of precedent

LS.02 — Sources of Law & Doctrine of Precedent

Sources of law (hierarchy)

• Acts of Parliament (primary legislation) — supreme source. Courts apply them; they cannot strike them down (parliamentary sovereignty).
• Delegated/secondary legislation (SIs, byelaws, regulations) — made under enabling Act; can be challenged by judicial review for ultra vires.
• Case law (common law + equity) — judge-made; binding via precedent.
• Retained/assimilated EU law — see below.

Doctrine of precedent (stare decisis)

• Only the ratio decidendi (legal reason for the decision) binds. Obiter dicta are persuasive only.
• Vertical binding: lower courts bound by higher courts.
• Horizontal: Supreme Court can depart from its own decisions (Practice Statement 1966); Court of Appeal generally bound by itself, with the Young v Bristol Aeroplane [1944] exceptions (conflicting CA decisions, conflict with later SC/HL decision, per incuriam).
• Avoiding precedent: distinguishing (material facts differ), overruling (higher court), reversing (same case on appeal).
• Court hierarchy: Supreme Court → Court of Appeal → High Court → County/Crown/Magistrates.
• Within the High Court: a decision of a single High Court judge does not bind another High Court judge (it is persuasive and normally followed unless the later judge is convinced it is wrong). A single judge is generally bound by a decision of a Divisional Court (two or more judges) exercising appellate jurisdiction; a Divisional Court sitting at first instance (for example in judicial review) is in the same position as a single judge (R v Greater Manchester Coroner, ex p Tal [1985] QB 67). Where first-instance decisions conflict, the later one should normally be followed if it fully considered the earlier (Colchester Estates v Carlton Industries [1986] Ch 80); a later decision does not formally overrule an earlier one.

Statutory interpretation

• Literal, golden, mischief rules; modern courts favour the purposive approach.
• Aids: intrinsic (long title, headings) and extrinsic (Hansard under Pepper v Hart [1993], dictionaries, Interpretation Act 1978).
• Rebuttable presumptions; rules of language (ejusdem generis, expressio unius).
• HRA 1998 s.3: read legislation compatibly with ECHR "so far as possible"; if impossible, s.4 declaration of incompatibility (does NOT strike down the Act).

EU / assimilated law (current)

• REUL Act 2023 renamed retained EU law to "assimilated law" and ended EU supremacy from 1 Jan 2024.
• Trap: REUL Act 2023 s.6 (new departure test + lower-court reference route) never came into force (commencement revoked by SI 2024/976). The EUWA 2018 s.6 framework still governs: the Supreme Court may depart from assimilated EU case law applying its own test for departing from its decisions, and the Court of Appeal (with the other relevant courts under the 2020 Relevant Court Regulations) may depart applying the same test the Supreme Court would apply (reg 5), not its own narrower test; lower courts/tribunals remain bound.

Common traps

• Precedent binds on the ratio, not the outcome or obiter.
• Court of Appeal is not free like the Supreme Court — Young exceptions only.
• Pepper v Hart is narrow (ambiguity + clear ministerial statement).
• s.4 HRA gives a declaration, never invalidation of primary legislation.
• Use "assimilated law", not "retained EU law", post-2024; do not cite the dead REUL s.6 test.

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