Andy Burnham, the popular mayor of Greater Manchester and the politician many in Labour view as the party’s best hope to lead, will gamble his mayoralty on a special election in Makerfield — a seat northwest of Manchester where Reform UK swept the local wards — to reclaim a place in Parliament and mount a challenge to embattled Prime Minister Keir Starmer.

The path to Parliament opened Thursday when Labour lawmaker Josh Simons said he would step down to make way for Burnham. Labour’s executive body cleared Burnham to run in the special election expected within weeks. The 56-year-old Burnham, known as the “King of the North” for his fierce advocacy of northern England’s working-class culture, has been out of Parliament for 16 years but has built a reputation as the most effective communicator in Labour’s ranks. His standing grew during the COVID-19 pandemic when he became a de facto spokesman for the north, constantly haranguing then–Prime Minister Boris Johnson over a “London-centric” approach to the crisis.

Burnham would have to quit his job as mayor if he wins, but his supporters see the race as a necessary step toward a broader reckoning for Labour, which suffered a severe beating in this month’s nationwide local elections. More than a fifth of Labour’s 403 MPs have urged Starmer to stand down, and his approval ratings have collapsed.

“We need to fix politics, to fix the economy, get the basics back under public control so that people can afford their rent, energy bills, etc.,” Burnham told the BBC on Saturday. “We’ve got to see this as a moment to reclaim the Labour Party, to save it from where it’s been. we can’t just carry on as we are.”

The path through Makerfield, however, runs directly through Reform UK. The anti-immigrant party led by Nigel Farage won all the wards in the constituency during the local elections, and Farage said the party would “throw absolutely everything at it.” Simons secured the seat by about 5,400 votes in Labour’s 2024 landslide, but the political landscape has shifted dramatically.

“There will be a lot of people who would like to see him get back into Parliament, not least to take down Keir Starmer,” said Tim Bale, a professor of politics at Queen Mary University of London. “In some ways, it’s a useful test for Burnham because if he can’t beat Reform in that constituency, then quite frankly, he’s not much use to the Labour Party as leader.”

If Burnham wins the by-election, he could either trigger a leadership contest or join one. To do so requires the support of at least 81 Labour MPs. Starmer has vowed to fight on and would automatically be entitled to run.

Wes Streeting, who resigned as health secretary on Thursday, confirmed he would be a candidate. “We need a proper contest with the best candidates on the field, and I’ll be standing,” he said. Streeting insisted he had enough support to trigger a contest but suggested the field would “lack legitimacy” without Burnham having a chance to return to Parliament. Streeting also voiced hope that the U.K. would eventually rejoin the European Union and warned that Labour risked becoming “the handmaidens of Nigel Farage” if it ignored the electorate’s warnings.

Others said to be considering a bid include former Deputy Prime Minister Angela Rayner, defense minister Al Carns, and former party leader Ed Miliband.

For now, all permutations go through Makerfield. Bale said that if Burnham wins, “it’s unlikely that Keir Starmer will actually stand in that leadership contest. If Burnham fails, then Starmer might feel he has a chance against Streeting and Rayner.”