How is the prime minister chosen?

The UK Prime Minister is not directly elected. The King appoints the person most likely to command the confidence of the House of Commons. This is normally the leader of the largest party after a general election. If a Prime Minister resigns mid-term, their party picks a new leader, who usually becomes Prime Minister.

At a general election, voters choose their local MP. The party that wins most seats usually forms the government, and its leader is invited to Buckingham Palace to become Prime Minister. In a hung parliament, the sitting Prime Minister stays until it is clear who can win a confidence vote. The new Prime Minister then forms a government and appoints the Cabinet.

Prime Ministers often change between elections. Each party sets its own leadership rules. In the Labour Party, candidates need nominations from 20% of the party's MPs, then members vote. In the Conservative Party, MPs narrow the field and members choose between the final two. Other parties have their own rules. In each case, the person who wins becomes Prime Minister only if their party can command a Commons majority.

This happened in 2026. The Prime Minister announced his resignation in June, and a new governing party leader was elected unopposed in July. The new leader became Prime Minister on 20 July 2026, without a general election. By convention the Prime Minister sits in the House of Commons, which is why some leaders enter Parliament through a by-election first.