How Britain gets its next prime minister: the handover process explained

Sir Keir Starmer's resignation does not, by itself, change who lives in Downing Street. Because the prime minister is the leader of the largest party in the House of Commons, the question of who succeeds him is, in the first instance, a matter for the Labour Party. Only once Labour has chosen a new leader will there be a formal change of government, marked by an audience with the King.

Until that point, Sir Keir remains in office as a caretaker prime minister, leading the government but expected to avoid major new commitments while the contest plays out.

The timetable

Labour has set out a clear schedule. Nominations for the leadership are due to open on 9 July and to close on 16 July, when Parliament rises for its summer recess. If more than one candidate qualifies, the contest will run over the summer, with the aim of having a new leader in place before MPs return in September.

To get onto the ballot, a candidate needs the backing of a significant share of Labour MPs, reported to be at least 81, equivalent to a fifth of the parliamentary party. If two or more clear that threshold, the final choice falls to the wider membership in a ballot, with longstanding members able to take part.

“The prime minister remains in office until they resign to the Sovereign, at which point the King invites the person best able to command the confidence of the Commons to form a government.”

The role of the King

The monarch's part in the process is formal but essential. Sir Keir informed King Charles III of his intention to resign on Monday morning, but he will not tender his actual resignation until Labour has a new leader ready to take over. At that moment the King will accept Sir Keir's resignation and invite the new Labour leader to form a government, a sequence designed to ensure the country is never without a prime minister.

This is the convention that has governed every recent change of prime minister between general elections, and it is why an outgoing leader stays on rather than leaving an immediate vacuum at the top of government.

• Sir Keir remains caretaker prime minister until a new Labour leader is chosen.
• Leadership nominations open on 9 July and close on 16 July 2026.
• Candidates need the backing of at least 81 Labour MPs to stand.
• If there is a contest, Labour members decide in a ballot over the summer.
• A new leader is expected to be in place before Parliament returns in September.

Background

The procedure echoes recent Conservative leadership changes, when prime ministers stayed on as caretakers while their parties ran internal contests to choose a successor. The UK has no separate election for prime minister; the office is held by whoever can command the confidence of the Commons, which in practice means the leader of the governing party. Andy Burnham, having won a Commons seat in the Makerfield by-election, is now eligible to stand and is the early frontrunner.

What happens next is the formal opening of nominations in July. If Burnham faces a credible challenger the contest will run into the summer; if rivals stand aside, as some early signals suggested, the party could install its new leader, and the country its new prime minister, considerably sooner.