Paul SeddonPolitical reporter
Sir Keir Starmer has announced his resignation as Labour leader, heralding the end of his time in 10 Downing Street.
He has said he will stay on as UK prime minister until his successor is in place.
Why did Starmer resign?
Pressure on the Labour leader had been building for a while, amid dire approval ratings for the party generally and him personally.
His premiership was further destabilised earlier this year, after the release of documents by the US Department of Justice reignited a scandal over his decision to make Peter Mandelson his US ambassador.
A damaging by-election defeat in February, where Labour lost a formerly safe seat to the Greens after Sir Keir blocked the then Greater Manchester mayor Andy Burnham from standing, turned a series of local and national elections in May into a litmus test of his leadership.
The results of those May elections were devastating, even worse than many in the party feared, prompting Wes Streeting to resign as health secretary as well as a clutch of more junior ministers.
Sir Keir fought on, but his authority ebbed further when a long-simmering row behind the scenes over defence spending prompted Labour stalwart John Healey to resign as defence secretary earlier this month.
Andy Burnham’s decisive victory at the Makerfield by-election last week, where he successfully held off a challenge from Reform UK, cleared a path for him to return to Westminster and launch a formal leadership bid.
After Burnham’s election, Sir Keir initially insisted he would contest any leadership challenge – before concluding over the weekend that Labour MPs wanted someone else to lead them into the next general election.
When might a new leader be selected?
We haven’t had the official timetable yet for the coming Labour leadership contest – the party says it will be agreed “shortly”.
But Sir Keir said he would ask Labour’s ruling National Executive Committee that nominations for a new leader open on 9 July, closing on 16 July when Parliament begins its summer recess.
Labour’s rulebook says that contenders have to be nominated by 81 Labour MPs to stand, limiting the potential pool of candidates to four.
They also have to win the support of at least 32 of Labour’s 634 local branches, or three organisations affiliated to the party (including two trade unions).
Once this window closes, contenders who have reached the nomination threshold would face a vote among party members and affiliated trade union supporters.
This would likely be accompanied by a series of party hustings and TV debates taking place over the summer, as contenders make their pitch.
Sir Keir says that if this is the case, a new leader should be in place by the time Parliament returns from its summer break on 1 September.
Will there be a vote?
But as things stand, it is not at all clear whether such a vote will be needed.
Burnham, who is due to be formally sworn in as an MP later on Monday, has confirmed he will be putting himself forward.
However, former health secretary Wes Streeting, seen as a potential leadership rival, has ruled himself out and thrown his weight behind Burnham.
Other potential contenders, including former deputy leader Angela Rayner, are yet to say whether they intend to stand.
If no other MP throws their hat in the ring, Burnham would become leader without the need for a vote, rapidly accelerating his entry into No 10.