Keir Starmer on brink of resignation as over 100 Labour MPs demand his exit after Burnham’s by-election win

The by-election that changed the calculus

Andy Burnham, the outgoing mayor of Greater Manchester, won the Makerfield by-election on Thursday with 55% of the vote, securing a seat in the Commons and the right to challenge Starmer for the Labour leadership. The result, described by Burnham as a potential "turning point", instantly emboldened critics of the prime minister. Within 48 hours, the number of Labour MPs publicly calling for Starmer to go surpassed 100 out of the party’s 403 MPs, according to a count cited by the British press.

Weekend at Chequers and the shift in mood

Starmer spent the weekend at his official country residence, Chequers, discussing his future with his wife Victoria and a tight circle of advisors. The Observer reported that senior party figures expect a "clear statement" as early as Monday. Peter Kyle, the business minister, told the BBC that Starmer was reflecting on "political realities" and had asked repeatedly for advice on what the country wanted. Despite that, Kyle publicly denied that a resignation was certain. One friend of the prime minister said:

Only one option remains. I think he has come to see that as the option duty demands, to serve the country and the party.

Cabinet ultimatum and the threat of mass walkouts

Pressure from the parliamentary party hardened over the weekend. The Telegraph reported that four cabinet ministers (Shabana Mahmood, Ed Miliband, Heidi Alexander and Yvette Cooper) have already urged Starmer to stand down. Other ministers are said to have delivered an ultimatum: resign or set a departure date by Tuesday, or face a wave of cabinet resignations during the scheduled council of ministers that day. A formerly loyal MP told the Telegraph:

There is nobody left. Literally, only people who have family working in No 10 or are longtime personal friends of Keir are still with him.

The succession battle begins

Andy Burnham is the clear favourite to succeed Starmer. His by-election victory was won against a far‑right populist, and his campaign emphasised hope and optimism. Burnham has already declared his intention to challenge for the leadership, though he has not set a timetable. Wes Streeting, a former health secretary, is also weighing a bid. Between 200 and 300 Labour MPs are reportedly ready to sign nomination papers backing Burnham the moment the contest opens, a tally that would almost certainly force a quick resolution.

What happens next

Should Starmer announce his resignation on Monday, he is expected to set a timetable for a gradual exit, possibly aiming to leave Downing Street around the Labour Party conference at the end of September. ITV’s Robert Peston suggested that approach would avoid a "civil war" reminiscent of the Conservative Party’s rapid turnover of five prime ministers between 2016 and 2024. Starmer himself posted a congratulatory message to Burnham on Friday, calling his campaign one of "hope and optimism over division and hate". The next 48 hours will determine whether the prime minister can manage an orderly transition or faces a forced ejection by his own cabinet.