Sir Keir Starmer's premiership has never looked more vulnerable as growing numbers of his own MPs call on him to stand down after a disastrous set of election results.
The prime minister has vowed to fight on, even suggesting he could serve two terms, but the choice could very soon be taken out of his hands.
It is a fast moving and volatile situation, but here are some scenarios on how things might play out in the coming days and weeks.
The Labour backbencher Catherine West surprised everyone on Saturday by announcing that she was prepared to challenge Sir Keir for the party leadership.
She's never had a high profile in the party. But Sir Keir gave her a junior ministerial job in the Foreign Office after Labour's election win in 2024. He sacked her when he reshuffled his government last year.
