The British constitution

Unlike many other countries, the United Kingdom does not have a single written constitution. Instead, the British constitution is made up of a collection of laws, conventions, court judgements, and historical documents that together define how the country is governed.

The UK constitution is described as uncodified — meaning it is not contained in a single document. It is instead made up of:

• Acts of Parliament — laws such as the Magna Carta (1215), the Bill of Rights (1689), and the Human Rights Act (1998)
• Common law — legal principles established by the courts over centuries
• Conventions — unwritten rules widely respected in practice, such as the convention that the monarch follows the advice of the Prime Minister
• Works of authority — scholarly and constitutional texts that explain how the constitution works

The United Kingdom is a constitutional monarchy. The monarch (currently King Charles III) is the head of state, but the actual power to govern rests with Parliament and the elected government.

The monarch's constitutional role includes:

• Opening Parliament — delivers the King's Speech at the opening of each parliamentary session, setting out the government's programme
• Appointing the Prime Minister — by convention, appoints the leader of the party with a Commons majority
• Giving Royal Assent — formal approval of new laws passed by Parliament; in practice, never refused
• Head of the Armed Forces — formal Commander-in-Chief of the armed forces

Parliament is the supreme legislative authority in the UK, made up of:

• The House of Commons
• The House of Lords
• The Monarch (in their constitutional role)

The House of Commons is the elected chamber with 650 Members of Parliament (MPs), each representing a constituency. MPs are elected through a general election, held at least every five years.

The Speaker chairs Commons debates and must remain strictly impartial — voting only in the case of a tie.

The House of Lords is the unelected second chamber. Members include:

• Life Peers — appointed by the monarch on the advice of the Prime Minister
• Hereditary Peers — a small number who inherited their title; most were removed by the House of Lords Act 1999
• Lords Spiritual — the Archbishops of Canterbury and York and 24 Church of England bishops

The Lords scrutinise legislation and suggest amendments but cannot permanently block laws passed by the Commons — under the Parliament Acts 1911 and 1949, the Commons can ultimately pass a law without the Lords' consent.

The Prime Minister is the head of the government and the most powerful elected official in the UK. The Prime Minister:

• Leads the Cabinet — approximately 20 senior ministers heading key government departments
• Sets government policy
• Lives and works at 10 Downing Street in London

Since 1999, some powers have been devolved to:

• Scottish Parliament at Holyrood, Edinburgh — health, education, justice, and some taxation
• Senedd Cymru (Welsh Parliament) in Cardiff — health, education, and other areas
• Northern Ireland Assembly at Stormont, Belfast — education, agriculture, and other matters

England has no devolved Parliament and is governed directly by the UK Parliament.

Up next: The government — explore how the UK government works in practice, including how laws are made and how the civil service supports ministers.