LABOUR will be plunged into a leadership contest next week despite desperate efforts by Sir Keir Starmer to buy off his main rival, Greater Manchester Mayor Andy Burnham.

The Prime Minister said he would offer Mr Burnham a big job in the cabinet if he wins Thursday’s by-election in Makerfield, which opinion polls in the constituency suggest he is on course to do.

Sir Keir also warned against a leadership contest on the grounds that the party should be focused on the election for Greater Manchester mayor, which would automatically follow Mr Burnham’s return to the Commons.

However, Mr Burnham is not going to be moved by any of these blandishments. He has indicated that he will, upon election in Makerfield, immediately press Sir Keir to set out a timetable for an election for his job and will not accept a government post under him.

His aides also point out that winning the Manchester mayoralty for Labour, in the face of what will certainly be a very strong challenge by the hard-right Reform UK, will be easier if Sir Keir is seen to be on the way out, such is his personal unpopularity.

Moreover, former health secretary Wes Streeting has made it explicit that he will push for a leadership election at the start of next week come what may.

The darling of the Blairites claims he has the support of the 81 MPs needed to trigger such a contest, which he did not when he last tried after the disastrous May elections.

Labour MP Rachael Maskell, who led the backbench rebellion that forced the government to back down on welfare cuts last year, urged Mr Burnham to strike while the iron is hot if he wins the by-election.

Speaking while out canvassing in Makerfield, she said: “We need to move forward. This country is crying out for his leadership.

“He needs to get sworn in and after that we need to look at the leadership and make sure we can form a good cohesive Labour government on the back of it.

“I’m optimistic that can happen really quickly.”

Sir Keir’s authority continues to crumble as the day of reckoning approaches.

Energy Secretary Ed Miliband reportedly simply refused to take the Prime Minister’s calls at the height of last week’s row over arms spending, and other cabinet ministers are said to be ready to resign if Sir Keir does not finally agree to step down.

Mr Burnham spent the last campaigning day in Makerfield elaborating on his agenda. He said: “It’s about changing politics, it’s about writing a new script really and that’s what the people here can do.

“I said at the start we’ve had 40 years of trickle-down economics. It’s not trickled down very much, or not enough to here, 40 years of neoliberalism, and we’ve not been saying that for a long time.

“How do you build an economy that works for places like this and many hundreds of other places like it throughout the country?”

The Labour candidate also claimed that his position on Gaza was clear, which is contested.

“I was one of those who called for a ceasefire shortly after the events of October 7. I have spoken out, taken a clear stance on these matters and have done over many years,” he said.

Sir Keir said that if Mr Burnham wins, “we’re immediately tipped into a Manchester mayoral contest by-election, one of the biggest by-elections that we’ve ever fought.

“And it’s really important that the whole of the Labour Party and Labour movement focuses on that, which is the next most immediate task.”

Wooing his rival, the premier said: “Andy is a huge asset to our party and our movement. He’ll play a big part in the Labour government.”

He repeated that if there was a challenge to his position he would contest it, as the incumbent Sir Keir would automatically be on the ballot for any election should he choose to be.

“I’m not going to walk away from that, and I’ve been clear and consistent about that,” he said.