LONDON — Andy Burnham took his first step to potentially becoming the next British prime minister Friday, winning a special election in the small northwest England area of Makerfield.

Burnham, the mayor of Greater Manchester, has openly discussed mounting an effort to replace Keir Starmer, the current prime minister, as leader of the ruling center-left Labour Party. Starmer is historically unpopular in Britain after a series of scandals and policy missteps, with critics accusing him of lacking a political vision for remedying the country’s stagnant post-Brexit economy.

Winning Thursday’s election secures Burnham’s return to Parliament and clears the path for him to bring a challenge against Starmer. Mutinous Labour MPs have been openly calling for a change of leader for months, fearful that Starmer would lead the party to a defeat in the next election and usher in the hard-right Reform UK, led by Donald Trump ally Nigel Farage.

The results of the special election, called a “by-election” in Britain, came in early Friday showing Burnham had defeated his Reform opponent, Robert Kenyon, by 24,927 votes to 15,696.

“Everyone knows that politics isn’t working. Everyone can feel that the country isn’t where it should be. Tonight could, just could, be the turning point,” Burnham said on stage after the result was announced.

Burnham characterized the vote as a vote for change. “This result will bring about a country that works fairly for everywhere and for everybody,” he said.

British by-elections are often sleepy affairs with results that are foregone conclusions, but the battle in Makerfield has been closely watched due to its national significance and the unusual circumstances by which it came about. The area’s Labour MP, Josh Simons, resigned with the deliberate intent of allowing Burnham to win the seat, enter Parliament and seek the leadership.

The area, a working-class and largely white part of Greater Manchester, is a top target for Farage’s party, but Burnham sought to turn back the tide, relying on his unique appeal as the region’s popular mayor.

Reform’s own campaign faced setbacks over unearthed social media posts from Kenyon, a former plumber who previously described himself online as a “sexist” and said some women had abortions for “vanity purposes.”

To become leader, Burnham now needs to issue an official leadership challenge to Starmer, which itself requires the support of 81 fellow Labour lawmakers. He would then need to defeat Starmer, who has vowed to defend his own position by running in the ensuing contest himself rather than step aside.

The prime minister’s position looks fragile; some 110 of his own colleagues have already signed a letter calling for him to step down. Also running against him would be Wes Streeting, who last month resigned as health secretary to plan his own leadership challenge.

“Burnham’s win, while expected, will be greeted by his newfound colleagues at Westminster with a sigh of relief but also a degree of trepidation,” said Tim Bale, a politics professor at Queen Mary University of London.

“So far, he’s been something of a fantasy leader, a screen onto which supporters can project their pet theories as to how the government can turn things around,” Bale said. “Now, presuming he takes over from Starmer, that fantasy will collide with reality — and reality always wins.”

Claire Ainsley, Starmer’s former policy guru, credited Burnham with running a “positive campaign focused on hyperlocal issues that matter to people in the constituency of Makerfield, like waste and local services.”

Ainsley, who is now a director at the Progressive Policy Institute, a Washington think tank, added that it was “the kind of campaign that is winning for center-left candidates in other countries, which shows local people their candidate will put them and their area above partisan politics.”

This is a developing story. Please check back for updates.