Andy Burnham’s campaign has been forced to talk ministers out of resigning as early as this weekend to avoid Keir Starmer’s government descending into chaos amid fallout from the Makerfield byelection, the Guardian can reveal.

As they prepare for a potential change of leader in the event he beats Reform on Thursday, Burnham’s team is increasingly concerned a rapid collapse of Starmer’s administration would mean further instability for the country.

Senior campaign figures believe Starmer should be given time to set out a timetable for his departure, with Burnham not planning to announce any challenge in the immediate aftermath of the result.

However, some ministers are “trigger happy” and have already proactively offered to quit, Burnham allies revealed, suggesting that several below cabinet level could resign over the coming days to try to pressurise Starmer.

“We’re trying to hold that back. We can’t have a Boris Johnson-style collapse. If they’re trying to force Keir’s hand with a kamikaze approach it will ultimately be counterproductive,” a senior campaign figure said.

The prime minister has insisted he will fight any challenge, believing he has a duty to the country, even though some of his closest allies predict the leadership crisis may reach a tipping point where he has no option but to stand down.

Starmer’s allies have discussed a “100m hurdles” strategy which involves throwing obstacles in Burnham’s way – such as the danger of losing the Manchester mayoralty, the fragile geopolitical situation and potentially a job offer.

Supporters of Burnham expect senior cabinet ministers to tell the prime minister over the weekend to agree to a handover of power, rather than fighting a bitter leadership contest that could stretch on for months.

“We want to give Keir time and space to come to terms with the reality of his situation. Andy wants a managed transition. It’s what Labour MPs want. We need to keep the government on track,” a close Burnham ally said.

“Andy won’t be launching an immediate challenge or laying down the gauntlet in the early hours of Friday or over the weekend. He wants it to be as bloodless as possible.”

The Guardian can reveal that Burnham met Wes Streeting – a putative leadership rival even though many MPs remain sceptical he has the numbers – in Makerfield on Monday. Aides denied there had been a Granita-style pact over the timing of any contest.

The pair had independently come to the view that Starmer should be given time to reflect on his position, they said. “No deals were done,” one source said.

Starmer has said he expects to talk to Burnham “after the weekend”. But close allies of the Labour mayor warned that clinging on to power for more than a few weeks would result in Burnham triggering a contest.

“We would rather this happens in a dignified and respectful way. There are big challenges facing the country so it would be much better … But if he digs in at Downing Street then we’ll force him out,” a senior campaign figure said.

The Burnham camp believes that if Starmer does accept his days are numbered, then a speedy handover could follow. “Andy could hoover up nominations and – if he’s unchallenged – then in a week or two it’s job done.”

At the G7 summit in Evian on Wednesday, Starmer indicated he would give Burnham a cabinet job if he returned to Westminster. But allies of the Labour mayor said he would not be interested.

Although team Burnham has said they want to avoid ministerial resignations, cabinet ministers including Steve Reed and Darren Jones are said to have counselled Starmer he should proactively sack any cabinet ministers who tell him to resign or that they have lost confidence.

But others are sceptical of such a move because of the need to preserve government stability. The energy secretary, Ed Miliband, and the culture secretary, Lisa Nandy, are already on resignation watch, No 10 insiders said.

The Burnham camp has denied that any MPs have already been offered jobs, suggesting this would be premature. “We’ve been very disciplined. No horse trading,” one said. “But the cabinet has got to look completely different.”

They added that – if Burnham returns to Westminster – his priority would be a programme for government, including policies and changes to the system including potentially the way PMQs and communications are done.

While Burnham is expected to win Makerfield, Starmer loyalists believe he needs an “oh fuck” moment when the result drops to prove to Labour MPs that he could be the answer to beating Reform. This could be a large majority or beating the combined Reform and Restore vote.

Many Labour backbenchers remain sceptical about Burnham. “He’s totally underprepared and heading straight into a firestorm,” one said. Another said he was “seriously underpowered” on foreign policy and defence.

His allies point to his experience as a cabinet minister and mayor, saying that transition and policy teams have been operating for weeks. But they accept an orderly transfer of power would give him much needed time.

For now, Starmer appears determined to fight on, arguing that he won a big election mandate and has years until the next election, and that Burnham is untested and would face exactly the same challenges.

Loyalist MPs were invited to No 10 on Wednesday night to discuss a fightback strategy. There are reports of a campaign infrastructure in place including a campaign director and a bank account for donations.

Morgan McSweeney, Starmer’s former chief of staff who quit over the Mandelson scandal, has written a memo which has been circulated around No 10 staff. Sources said it included ideas for the team to get back on the front foot, but was not a detailed plan to secure his leadership.

Friends of McSweeney said that reports he was regularly advising Starmer were wide of the mark. They have spoken only half a dozen times since he left in February, and last talked on the phone a week ago. McSweeney has also privately ruled out helping with a leadership contest.

Labour MPs who want Starmer to survive, and the party to avoid a contest, are dismayed that he has not addressed the parliamentary Labour party since the disastrous local elections results that plunged his leadership into crisis.

“We need Keir to looks us in the eye and make the case for a fight,” one said. “If he can’t even come and talk to us, how is he going to run in a leadership contest?” a second added.

Even Starmer’s closest allies acknowledge he faces an extremely narrow path to political survival – and may struggle to convince MPs he can turn things around sufficiently, when so many people feel he has not so far.

“It depends on how much fight he’s got in him. He’s got to feel that he can take on the argument against him,” one said. “Keir doesn’t think he should make it easy for Andy just to take over,” another added. “But he does know that in the end he may not be able to stop him”.