# Sources of the UK constitution

> **Key takeaway:** Uncodified mix: statutes, common law, prerogative, conventions, dualist international law. Constitutional statutes (Thoburn). Conventions mainly political. Legality classic: Entick. Modern landmark: Miller (No 1).

- **Jurisdiction:** England & Wales
- **Practice area:** Public Law
- **Last reviewed:** 2026-08-04
- **Interactive page:** https://kttclegal.info/library/notes/PublicLaw/sources-of-the-constitution
- **Keywords:** sources of the constitution, uncodified constitution, constitutional statute, convention, prerogative, Entick v Carrington, Thoburn, Miller

## What is this about?

The UK has no single codified constitutional document. Its constitution is assembled from statutes, common law, constitutional conventions, prerogative powers, and works of authority. Understanding source hierarchy and the political nature of many rules is essential to public-law analysis.

## What is the core rule?

Principal sources include: (1) constitutional statutes (e.g. Bill of Rights 1689, Act of Settlement, Parliament Acts, Human Rights Act 1998, devolution statutes, EUWA 2018 as amended); (2) common law principles (legality, access to courts, residual liberties); (3) royal prerogative (executive powers recognised by common law); (4) conventions (politically binding but not ordinarily judicially enforced — e.g. Sewel, ministerial responsibility); (5) international law as dualist influence once incorporated; and (6) authoritative writings (Dicey, Jennings) as persuasive maps rather than binding law.

## What are the elements or test?

1. Is the rule statutory, common-law, prerogative, or conventional?
2. If conventional: is there a legal question the court can decide, or only political enforcement?
3. If statutory: ordinary or 'constitutional' statute for implied-repeal analysis?
4. Any HRA or devolution overlay?
5. Remedies: JR, declaration, political accountability?

## Which authorities matter?

- **Bill of Rights 1689; Act of Settlement 1701** — Historic statutory foundations of parliamentary and judicial settlement after the Glorious Revolution.
- **Entick v Carrington (1765) 19 St Tr 1029** — Classic common-law legality: executive interference with property requires positive legal authority.
- **Thoburn v Sunderland City Council [2002] EWHC 195 (Admin), [2003] QB 151** — Influential account of constitutional statutes and resistance to implied repeal.
- **R (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5, [2018] AC 61** — Supreme Court on domestic legal requirements for giving notice to leave the EU — interaction of statute, prerogative, and constitutional principle.

## How does this apply in practice?

Pair with parliamentary sovereignty, HRA, prerogative, and devolution notes. Conventions matter enormously in practice but rarely found free-standing causes of action. Always identify whether the client needs a legal remedy or a political strategy.

## What are common pitfalls?

- Treating Dicey as if it were a statute
- Assuming courts will enforce every convention
- Ignoring devolution statutes as constitutional sources
- Conflating international obligations with domestic law without incorporation

## When would a practitioner use this?

Framing public-law opinions, JR grounds selection, and constitutional litigation strategy.

## Quick reference

Uncodified mix: statutes, common law, prerogative, conventions, dualist international law. Constitutional statutes (Thoburn). Conventions mainly political. Legality classic: Entick. Modern landmark: Miller (No 1).

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*Reference material from [KTTC Legal](https://kttclegal.info/), not legal advice. Work product supports instructing solicitors and barristers under their supervision. England & Wales.*