London, UK - Veteran UK Labour politician Andy Burnham emphatically won a crunch by-election on Friday, securing a parliamentary seat and clearing the way for a widely expected leadership challenge against beleaguered Prime Minister Keir Starmer.
Burnham, a former government minister who has been Greater Manchester mayor since 2017, ensured his return to parliament by easily beating the hard-right Reform UK party's candidate in the Makerfield constituency in northwest England.
The 56-year-old longtime figure in center-left Labour wants to replace Starmer as party leader and prime minister, and needed to win the high-stakes vote to be in a position to trigger such a contest.
If Starmer does leave office this year, then Britain will get its seventh prime minister in 10 years.
"I do say to my own party, this is a final chance to change," Burnham said in his acceptance speech after securing nearly 55% of the vote, beating Reform's Robert Kenyon by more than 9,000 ballots. Turnout was a historically high 59%.
"We must get it right," he added, saying his victory could be a "turning point" for the country.
Starmer congratulated Burnham on X, saying voters "chose Labour's campaign of hope and optimism over division and hate."
The prime minister was expected to speak to media during a public appearance in London Friday morning.
In office since July 2024, Starmer has been clinging to power since Labour suffered a drubbing in polls in England, Scotland, and Wales last month.
Keir Starmer refuses to quit amid controversies
Starmer has been rocked by several policy U-turns and a scandal over his appointment of ex-Jeffrey Epstein associate Peter Mandelson as the UK's ambassador to Washington.
Dozens of Labour MPs have called on Starmer to quit, and several ministers have resigned, as national surveys suggest Reform is set to win the next general election, expected in 2029.
But the 63-year-old ex-lawyer has refused to quit, insisting his landslide election victory over the Conservatives 23 months ago gave him a five-year mandate to govern.
Amid growing impatience within the ruling party, now-former Labour MP Josh Simons stood down in Makerfield so that Burnham could try to return to parliament and run for leader.
The unprecedented move thrust the little-known political district into the spotlight, handing its electorate of roughly 77,000 people an outsized say in influencing Starmer's fate.
Surveys show that Burnham – nicknamed the "King of the North" for winning three consecutive mayoral terms – is Labour's most popular politician and would likely win a direct vote against Starmer amongst the party membership.
Thursday's vote for the Makerfield seat, where Labour had held a majority of just 5,300 votes, was seen as a test of whether Burnham can defeat Reform, led by anti-immigrant firebrand Nigel Farage.
The area is predominantly white and working-class – fertile territory for the hard-right group which has topped national surveys for over a year.
But local plumber Kenyon's campaign was dogged by past offensive remarks about women, while the fringe hard-right Restore Britain party dented Reform's vote by snagging nearly 7% of returns.
Does Andy Burnham's election spell trouble for Keir Starmer?
Starmer has vowed to fight any leadership challenge, but the resounding nature of Burnham's win is likely to heighten pressure from Labour MPs to step down instead.
A cascade of resignations from Starmer's top team would make his position untenable.
Before the Makerfield result was declared, ex-minister Louise Haigh told the BBC Starmer should consider "an orderly and managed transition" of power.
Burnham, an MP from 2001 to 2017, hails from Labour's so-called soft-left wing and has been an outspoken critic of Starmer's more-centrist rule.
Attention now turns to when he will make his move against Starmer.
Burnham is due to be sworn in as a member of parliament on Monday. Under Labour party rules, leadership candidates must be an MP.
He will be able to easily muster the support of 81 of Labour's 400-plus MPs – the minimum needed to kickstart a contest.
Ex-health minister Wes Streeting, from Labour's right wing, has said Starmer should be given "space over the weekend" to consider his future.
Streeting has also vowed to join any race, but could end up striking a deal with Burnham to avoid a divisive fight.
Speaking to the BBC, polling expert John Curtice cautioned against any suggestion that Burnham's victory would lead to a "dramatic" improvement in Labour's popularity nationwide.