Former deputy prime minister Angela Rayner does not want Andy Burnham to be blocked from standing in the Gorton and Denton by-election, the understands.
As first reported in The Times, Rayner is expected to publicly make her announcement at Labour’s north west regional conference on Saturday.
If Burnham did contest and win the by-election in Greater Manchester, it would enable him to mount a leadership challenge against Sir Keir Starmer.
The has been told that some of Sir Keir’s supporters on Labour’s ruling National Executive Committee (NEC) will seek to block him from standing.
The Greater Manchester mayor has until 5pm on Saturday to let the NEC know if he wants to stand or not – and he will find out on Sunday whether he will be allowed to.
Under Labour rules, elected mayors must get permission from the NEC before seeking nomination as Labour Parliamentary candidates.
The by-election could happen as early as next month after ex-Labour minister Andrew Gwynne formally resigned from the House of Commons, saying he had been advised by his GP not to return to work.
Burnham has not said if he will go for the seat, telling reporters on Thursday that he was “focused” on his role as Manchester mayor and that people shouldn’t “rush to conclusions”.
He has since refused requests for interviews.
The tight timetable puts pressure on Burnham to make a quick decision which could make or break his political career.
Rayner was forced to resign as deputy prime minister and housing secretary last year after the PM’s ethics adviser concluded she had breached the ministerial code.
However, she retains strong support among backbench MPs and party members and her backing for Burnham could make it harder for the NEC to block his progress.
Several Labour sources have said they expect the committee to object to Burnham’s candidacy on the grounds that it would trigger an election for the Greater Manchester mayoralty, which would be seen as a drain on party funds as well as politically risky.
The NEC could also insist that there should be an all-women shortlist of possible Labour candidates for a by-election because the majority of the party’s MPs are currently men.
Opinion among Labour MPs is divided over whether Burnham should come back to the Commons.
In a social media post appearing to back Burnham, Jo White, MP and leader of the Red Wall group said: “A London stitch up will be a disaster for Labour.”
However, Graham Stringer, the MP for Blackley and Middleton South in Greater Manchester, said Burnham was “entitled to be ambitious but this isn’t the right opportunity”.
“I think it’s very high-risk. By-elections are a nightmare for any candidates standing on behalf of a sitting government. I don’t think Andy should take that risk.”
Labour won the Gorton and Denton seat at the 2024 election with a 13,000 majority. Reform UK came second with 5,000 seats narrowly beating the Greens candidate into third place.
The area has traditionally been considered a safe seat, but Labour’s drop in popularity since the general election means the party are not guaranteed a win.
As the prime minister’s popularity has declined, speculation has grown that he could face a leadership challenge after the local elections in May, at which Labour is expected to perform poorly.
Alongside Burnham, Rayner and Health Secretary Wes Streeting have also been touted as possible challengers.
Speaking to the ‘s Political Thinking, Deputy Prime Minister David Lammy said: “I don’t know if Andy really wants to get back into Westminster politics.
“He may do, and there’s much merit to him.
“But I would caution those often around that start to destabilise the ship and say that we can have a new leader.
“No, we can’t. Because immediately you’d be forced to have an election.”