Starmer warned against 'stitch-up' as Greater Manchester by-election triggers Burnham’s Westminster return

Mr Burnham, long viewed as a potential rival to the Prime Minister for the Labour leadership, is reported to be putting his name forward to run in Gorton and Denton, after Andrew Gwynne formally resigned as MP.

Labour MPs warned against using the party’s ruling national executive committee to block Mr Burnham from standing.

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Jo White, who chairs the Red Wall group of Labour MPs, said: “Let the North decide who their Labour candidate should be for the Gorton and Denton by-election. A London stitch-up will be a disaster for Labour."

Crewe and Nantwich MP Connor Naismith said: "Gorton and Denton deserves the best possible choice of candidates. I agree with the Prime Minister that our attention should be on delivering for the public, not speculating about future leadership contests.

"Any decision made to limit the choice would be wrong."

Former deputy prime minister Angela Rayner is also expected to back Burnham standing for MP at Labour’s northwest regional conference on Saturday.

Mr Gwynne’s resignation was formalised on Friday with his appointment as Steward and Bailiff of the Manor of Northstead, one of the offices used in the archaic procedure that allows MPs to resign their seats.

His decision means a by-election in the constituency, which Labour won comfortably in 2024.

There are several other obstacles stopping Burnham taking the seat, such as the financial cost it would inflict on the Labour Party if he stepped down before his mayoral run ends in 2028.

By opening up a Manchester mayoral election, Burnham would be diverting campaign funds away from other Labour council seats in May as the party attempts to stop Reform winning.

His candidacy will also have to be approved by the NEC, which has been seen as under the control of Sir Keir’s supporters.

But the leaders of two unions represented on the committee warned against any move to block Mr Burnham.

Unison’s Andrea Egan said: “I’m sure all trade unionists expect a democratic process for Gorton and Denton in which local party members decide who they want to represent them.

“We’ve seen enough control-freakery in the Labour Party and it has done our movement nothing but harm.”

The Fire Brigades Union’s Steve Wright said: “It would be a democratic outrage if Andy Burnham was blocked from seeking selection as Labour’s by-election candidate in this seat.”

On Friday, Health and Social Care Minister Stephen Kinnock suggested on urnham should stay in his Greater Manchester comfort zone.

He told BBC Breakfast Burnham is “doing a great job in the role that he currently has” and is “an incredibly talented and effective leader as the mayor of Greater Manchester."

David Lammy also urged Burnham not to “rock the boat” by moving against Sir Keir Starmer.

The Deputy Prime Minister said any move to replace the PM would led to an early general election, which the party would be on track to lose.

"All of us are in the business of Labour politics and all of us have got to be seen to be getting on with serving working people," Lammy said.

"And parties that air their dirty linen in public, that fight and bitch and moan, usually are a huge turn-off to the electorate. We are in the midterms, that’s effectively what the elections in May represent.

"The midterms are always challenging for incumbent governments. In the end, we will be judged at the four, four-and-a-half, five-year point, which is some way off. And we will have to demonstrate to the British people improvement.

"Please do not let us rock the boat and blow it which Labour governments have done throughout their history. That was why Labour was only in power in the 20th century for 22 years. Let’s not make that mistake again."