What does Makerfield make of by-election and can Burnham win?

He also criticised the mayor's involvement in plans to introduce a Clean Air Zone scheme during lockdown, even though they were eventually dropped in 2022 and an alternative proposal was signed off by the government.

"I think Reform will take over. They really jumped in here in a massive way."

But Alan Entwistle, who works as a carpet cleaner, said the policies Burnham had implemented while mayor were "up there"

"He's done brilliantly with the buses and everything else," he said. "He knows what he's doing."

Gabriel Parkinson, who works in the charity sector, said she favoured the Green Party but would vote for Burnham in this by-election as "the choice we have against Reform".

If Burnham succeeds, a Labour leadership contest is likely to follow, potentially leading to a new occupant of Number 10 by the autumn.

The earliest a by-election could be held is on Thursday, 18 June - during the same week that Sir Keir is due to be at a G7 summit in France.

Before Burnham can run, he will need to be chosen as Labour's candidate by officers on the party's National Executive Committee (NEC).

The body previously blocked Burnham from standing in the Gorton and Denton by-election in February, but the BBC understands that the prime minister will not seek to block him this time around.

He will also have to be approved by the local Labour Party in Makerfield.

Burnham was re-elected for a second term as Greater Manchester mayor in May 2021 and a third in May 2024, with 63.4% of the vote - in Wigan, he received 66% of the vote.

Polling expert Sir John Curtice told Politico Labour would have "less than 5% chance" in the Makerfield by-election "if it were anyone other than Andy Burnham" as a candidate.

He added: "If [Burnham] manages to win this, he will certainly be demonstrating his ability to win constituencies you would expect most Labour politicians to lose at the moment."

Outgoing MP Josh Simons told the BBC that he was confident Burnham could win the seat, but admitted there was a "really tough fight" on his hands.

At the general election in 2024, Simons won the seat with 45.2% of the vote, a majority of 5,399. Reform came in second with 31.8% of the vote, with the Conservatives in third, Lib Dems in fourth and Greens in fifth.

The constituency boundaries were changed slightly in that election, but the seat has been Labour-held for decades.

This seat is 29th on Reform's target list and the party needs a swing of just over 6.7% to win it.

There are no precise figures for how the parties performed in Makerfield during the local elections because the ward boundaries do not fully align with the constituency boundaries.

But roughly, Reform pulled in 50% of the vote share, with Labour at 27%, the Greens at 10%, Conservatives at 7% and Lib Dems at 4%.

Reform gained 24 seats on Wigan Council, including in two wards in Ashton-in-Makefield.

Makerfield constituent Helen Raymond admitted to being "quite surprised" by how strongly the Reform vote grew at the local elections.

"But I think that maybe was a reaction to the current Labour leadership rather than giving up on Labour completely so I'm quietly optimistic," she said, pointing to Burnham's involving in the development of Leigh Sport Village and his response to illegal rubbish dumps as evidence he "does care about this area".

Richard Tice, Reform UK's deputy leader, said the party was aiming to "make Burnham history" and would be "throwing everything possible" at ensuring a "seismic" win in this by-election.

Meanwhile the Green Party has said it has started the selection process for its candidate.

The party won February's by-election in Gorton and Denton and made big gains in Manchester in last week's local elections.

But the party has downplayed its prospects in Makerfield.

Former Green leader Caroline Lucas said she hoped the party would not contest the seat in order to give Burnham the best chances of seeing off the challenge from Reform.

"There are times when it's more important to put country before party. This is one of them," she wrote on X.