Government of the United Kingdom

His Majesty's Government, abbreviated to HM Government or otherwise UK Government, is the central executive authority of the United Kingdom of Great Britain and Northern Ireland. The government is led by the prime minister (Keir Starmer since 5 July 2024) who selects all the other ministers. The government is currently supported by the Labour party, which has had a majority in the House of Commons since 2024. The prime minister and his most senior ministers belong to the supreme decision-making committee, known as the Cabinet.

Ministers of the Crown are responsible to the House in which they sit; they make statements in that House and take questions from members of that House. For most senior ministers this is usually the elected House of Commons rather than the House of Lords. The government is dependent on Parliament to make primary legislation, and general elections are held at least once every five years to elect a new House of Commons, unless the prime minister advises the monarch to dissolve Parliament, in which case an election may be held sooner. After an election, the monarch selects as prime minister the leader of the party most likely to command the confidence of the House of Commons, usually by possessing a majority of MPs.

Under the uncodified British constitution, executive authority lies with the sovereign, although this authority is exercised only after receiving the advice of the Privy Council. In most cases the cabinet exercise power directly as leaders of the government departments, though some Cabinet positions are sinecures to a greater or lesser degree (for instance Chancellor of the Duchy of Lancaster or Lord Privy Seal).

The government is sometimes referred to by the metonym "Westminster" or "Whitehall", as many of its offices are situated there. These metonyms are used especially by members of the Scottish Government, Welsh Government and Northern Ireland Executive to differentiate their government from His Majesty's Government.

The United Kingdom is a constitutional monarchy in which the reigning monarch (that is, the king or queen who is the head of state at any given time) does not make any open political decisions. All political decisions are taken by the government and Parliament. This constitutional state of affairs is the result of a long history of constraining and reducing the political power of the monarch, beginning with Magna Carta in 1215.

Since the start of Edward VII's reign in 1901, by convention, the prime minister has been an elected member of Parliament (MP) and thus answerable to the House of Commons, although there were two weeks in 1963 when Alec Douglas-Home was first a member of the House of Lords and then of neither house. A similar convention applies to the position of chancellor of the exchequer. The last chancellor of the exchequer to be a member of the House of Lords was Lord Denman, who served for one month in 1834.

The British monarch is the head of state and the sovereign, but not the head of government. In practice, the monarch conventionally takes little direct part in governing the country and remains neutral in political affairs. However, the authority of the state that is vested in the sovereign, known as the Crown, remains the source of executive power exercised by the government.

In addition to explicit statutory authority, the Crown also possesses a body of powers in certain matters collectively known as the royal prerogative. These powers range from the authority to issue or withdraw passports to declarations of war. By long-standing convention, most of these powers are delegated from the sovereign to various ministers or other officers of the Crown, who may use them without having to obtain the consent of Parliament.