Andy Burnham will be the British Labour Party's candidate for the Makerfield bye-election, the party has announced.
It is understood that the Greater Manchester mayor was the only person shortlisted for selection by Labour's ruling National Executive Committee, bypassing a vote by the local party.
The decision sets up a contest between Mr Burnham and Reform UK's Robert Kenyon, a local plumber who contested the seat for the party in 2024.
Mr Burnham has put himself forward as the candidate to "change Labour", using a campaign video to call for a "new path for Britain".
If he returns to Parliament, Mr Burnham is widely expected to challenge Keir Starmer for the Labour leadership, but the Prime Minister has insisted he will not "walk away" from Downing Street.
Earlier today, Mr Starmer gathered his new-look Cabinet for the first time.
The regular Cabinet meeting was the first since Wes Streeting resigned as health secretary and called on the Prime Minister to quit last week.
Deputy Prime Minister David Lammy joked that it was "a nicer week than last week" as he arrived for the Downing Street meeting as Mr Starmer attempted to show the business of government was continuing despite the Westminster turmoil.
Meanwhile, Mr Burnham used a slick campaign video to set out his vision after saying his attempt to win the Makerfield bye-election was motivated by the need to "change Labour".
The bye-election was triggered by former minister Josh Simons quitting to make way for the Greater Manchester mayor to run for a return to Westminster.
Cabinet minister Pat McFadden, an ally of Mr Starmer, told reporters: "Any unnecessary bye-election is always a risk.
"It's the voters who have their say, but like any bye-election that is called for whatever reason, I want Labour to win."
Reform UK will target the seat and has already said the "expensive bye-election is all about (Mr Burnham's) own personal ambition" rather than the best interests of the constituency.
Mr Burnham said: "Some say this bye-election is unnecessary. I say it's the most consequential of our lives.
"I don't take anything for granted and I'm ready to accept the consequences of whatever choice people make."
Setting out his political views, he said: "Manchesterism is the end of neoliberalism, the end of trickle-down economics that has left out places like Makerfield.
"Make no mistake, that means a new path for Britain."
Mr Burnham has sought to reassure voters in the Leave-supporting Makerfield constituency that he is not seeking to rejoin the European Union - something he said last year he would like to see happen in his lifetime.
And he has also attempted to calm the bond markets by insisting he will stick to the government's fiscal rules.
Mr Starmer has insisted he will not set out a timetable for his departure even if the mayor returns to parliament.
If the Prime Minister does not resign, Mr Burnham would need to secure the backing of 81 Labour MPs to mount a leadership challenge, potentially setting up a contest with Mr Starmer for party members' votes.
But last night, one of Mr Burnham's supporters suggested the mayor would not seek an immediate leadership fight.
Leeds MP Alex Sobel told LBC it was not his "expectation" that Mr Burnham would immediately trigger a contest, saying he would "come back and potentially serve in the government, try and help us turn this government round".
Meanwhile, polling by YouGov suggested Mr Burnham would be Labour members' preferred candidate for leader, with 47% saying he would be their first choice for the job.
Some 31% ranked Mr Starmer as their first choice, followed by former deputy prime minister Angela Rayner on 8%.
Just 4% ranked Mr Streeting as their first choice, with 57% saying he was wrong to resign as health secretary and 15% backing him in a head-to-head contest with the Prime Minister.
In a contest between Mr Burnham and Mr Starmer, 59% said they would back the mayor while 37% would support the Prime Minister.
