What is a leadership election?

A leadership election is a contest within a political party to choose its leader. Each party sets its own rules, usually involving nominations from MPs and a ballot of members. If the governing party changes its leader, the new leader normally becomes Prime Minister without a general election.

In the Labour Party, candidates need nominations from a share of Labour MPs and from local parties or affiliated unions. Party members and affiliated supporters then vote. If only one candidate gets enough nominations, they are elected unopposed. In the Conservative Party, MPs vote in rounds to narrow the field to two, and members choose between them. Other parties have their own rules.

Leadership contests can be triggered by resignation, defeat or a formal challenge. In July 2026 Labour held a leadership election after the Prime Minister resigned following poor results in the May elections. Only one candidate secured enough nominations, so no ballot of members was needed. The new leader became Prime Minister on 20 July 2026. Labour's rules let the contest end early.

When a governing party changes leader mid-term, opponents often argue the new Prime Minister lacks a personal mandate. Supporters of the system point out that voters elect MPs and parties, not Prime Ministers directly. In 2022 two new Prime Ministers took office through party processes rather than general elections. Others argue it lets parties change course. Critics say voters, not members, should choose the Prime Minister.