UK PM Keir Starmer resigns - how soon could Britain get a new prime minister?

Tuesday, 23 June 2026

Andy Burnham could become Britain’s new prime minister by next month if no one challenges him in a leadership contest.

The timeline set out by Sir Keir Starmer as he resigned on Monday morning (UK time) means that he will mark two years in office, no matter the outcome.

The Labour leader said he would ask the party’s ruling National Executive Committee for the nomination stage of the leadership election to begin on July 9.

Sir Keir, who struggled to hold back tears while addressing the nation, said nominations would close “by the summer recess” on July 16.

This means Britain could have a new prime minister as early as July 17 if the candidate remains unopposed.

Following his victory in the Makerfield by-election last week, Mr Burnham is the clear favourite to replace Sir Keir.

Before being sworn in as an MP on Monday afternoon, the former mayor of Greater Manchester confirmed he would put himself forward to replace the Prime Minister.

Posting on social media, he said: “Keir has given huge service to our country and I want to thank him for his leadership and dedication during such a challenging period.

“His decision marks the beginning of a transition and it is important that this process is conducted in an orderly and responsible way. I will put myself forward as part of this process.”

Wes Streeting, who stepped down as health secretary last month and was thought to be considering challenging Mr Burnham, announced he would not be standing in a leadership contest.

While potential candidates need the backing of 81 MPs – a fifth of the Parliamentary Labour Party – to secure a spot in the leadership ballot, it is thought that Mr Burnham already has the support of around 200.

If another Labour MP puts themselves forward and has the necessary support, a contest will take place to decide who will become the leader of the Labour Party and the next prime minister.

In this case, the contest will take place during the summer and conclude by the time MPs return to the Commons on Sept 1.

During his speech, Sir Keir said he would “remain in post” as Prime Minister “until the contest is complete”, meaning he will effectively be the interim prime minister for the Nato summit on July 7 and 8 in Ankara, Turkey.

However, if Mr Burnham is unopposed, Sir Keir will not be able to attend the EU-UK summit scheduled to take place on July 22 in Brussels, in which he had hoped to seal new post-Brexit deals on food exports, youth mobility, electricity and trade.

On Monday, a spokesman for the European Commission said that it was “reassessing the opportunity” to hold the summit.

Following his resignation, Ursula von der Leyen, the president of the European Commission, said: “It can take many leaders years to grow into the statesman you became in just two years. European and Ukrainian security is stronger because of you. Thank you, dear Keir.”

The transfer of power has been quicker than on previous occasions, such as when Sir Keir was elected to be the leader of the Labour Party in 2020 – a process that took 38 days.