British Prime Minister Keir Starmer conceded on Monday that he had lost the support of his rank-and-file Labour Party members in Parliament and that he will step down once his successor as party leader is chosen, possibly as soon as the middle of July.

Andy Burnham, the former mayor of Greater Manchester whose resounding victory in a special UK election last week set in motion Starmer’s resignation, has confirmed he will put himself forward to be his successor.

Burnham is seen as the front-runner to replace Starmer, especially after his decisive victory on Thursday in the seat of Makerfield in northwest England, showing that he could appeal to voters across the political spectrum.

Despite Labour’s dismal poll ratings and substantial losses in local elections in May, Burnham defied electoral gravity. He was able to see off the challenge from the anti-immigration Reform UK candidate and mop up votes from other left-leaning political parties.

He substantially increased Labour’s share of the vote to nearly 55 per cent, which, if repeated on a similar scale across the country in the next general election, would no doubt see the party remain in power.

Though Starmer did not mention Burnham by name in his resignation statement outside the prime minister’s residence at 10 Downing Street, he conceded “with good grace” that he was not best placed to lead Labour into that election.