Keir Starmer’s grip on the U.K. premiership weakened sharply on Tuesday as dozens of lawmakers from his own centre-left Labour Party demanded he step down, days after the party’s disastrous performance in local elections, the Associated Press reported. Several junior ministers resigned from the government and publicly called on the prime minister to quit, deepening a crisis that has exposed deep discontent within Labour’s parliamentary ranks. Starmer has said he intends to stay on and “get on with governing,” but the revolt has set in motion a procedure that could see him forced out if more MPs turn against him.

According to the AP, about 80 Labour MPs have already said Starmer should announce a timetable for his departure. Under party rules, a leadership contest can be launched if a challenger secures the backing of at least 81 MPs — one-fifth of the party’s members in the House of Commons — and no candidate has yet come forward to try to dislodge the prime minister.

The simplest path to replacing Starmer would be his voluntary resignation. In that scenario, the Cabinet and Labour’s governing body would likely appoint an interim prime minister, such as Deputy Prime Minister David Lammy, while a formal leadership election proceeds. Candidates would need the support of 5% of local constituency parties or three affiliated groups, including trade unions, and the winner — chosen by a ranked ballot of party members and affiliates — would then be invited by King Charles III to form a government.

If Starmer refuses to go, he could face a direct challenge from one or more Labour MPs. The Conservative Party has a history of ejecting prime ministers midterm — Margaret Thatcher in 1990 and Boris Johnson in 2022 — but Labour has never removed a sitting leader. A unity candidate would need to clear the same nomination thresholds to appear on the ballot alongside Starmer.

A backbench MP, Catherine West, briefly said she would mount a leadership bid if the Cabinet did not force Starmer out by Monday, but she abandoned the plan the following day, acknowledging she lacked the required support. Her move was seen as an attempt to pressure more prominent figures to declare.

Those seen as potential successors include Health Secretary Wes Streeting and former deputy prime minister Angela Rayner, though Rayner resigned last year after acknowledging she underpaid tax on a house purchase and an investigation is ongoing. Andy Burnham, the popular mayor of Greater Manchester, is widely considered a strong candidate but cannot stand because he is not currently in Parliament. Labour officials earlier blocked him from running in a special election, but if Starmer signals he intends to stand down — possibly at the party’s annual conference in September — a Labour MP in a safe seat could step aside to allow Burnham to return to the Commons.

Starmer has shown no indication he is preparing to yield, and the next national election does not have to be called until 2029, giving any new leader time to reset the party’s fortunes before going to the country.