The only candidate to replace Sir Keir Starmer as Labour leader performed a migration U-turn on the campaign trail in Makerfield

Andy Burnham has been warned he risks sparking a Labour revolt before even becoming Prime Minister by backing Shabana Mahmood's migration reforms.

More than 80 Labour backbenchers have written to the Makerfield MP to urge him against "losing progressive voters" by supporting the Home Secretary's stance.

Under the proposals, asylum seekers would be required to pay back some of their taxpayer-funded hotel bills.

The legislation would also make it easier to deport illegal migrants.

Despite previously appearing critical of Ms Mahmood's reforms, Mr Burnham is now widely expected to back the bill.

The ex-Greater Manchester Mayor believes the reforms would make the immigration system fair for both asylum seekers and local communities.

A spokesman for Mr Burnham told HuffPost: "Andy believes the public deserve an asylum system that is both compassionate and credible.

"This bill takes important steps towards restoring confidence by tackling illegal crossings while strengthening safe and legal routes for genuine refugees.

"This is about ensuring the system is fair both to those seeking protection and to the communities that welcome them."

However, the decision to throw his weight behind Ms Mahmood will likely infuriate a large group of backbench Labour MPs.

In a letter sent to Mr Burnham last week, Labour's immigration rebels warned the proposals to increase Indefinite Leave to Remain for up to 20 years would leave the UK as an "international outlier".

It also argued it would weaken the UK's "soft power and our appeal as a place to study, invest, build a life and form relationships".

The letter continued: “This kind of policy making is anathema to who we are, what we stand for and how we should do politics.”

Labour rebels did not explicitly call for Mr Burnham to sack Ms Mahmood.

However, several MPs believe a drastic change of direction would force Ms Mahmood out of the Home Office.

An insider told The i Paper: "The Home Secretary, to be frank, is seen as toxic."

“There are profound concerns within the PLP about her [Mahmood’s] proposals," a Labour MP also said.

However, Mr Burnham's stance on migration has changed considerably since he decided to stand as Labour's candidate in the Makerfield by-election held last month.

He initially came out swinging against Ms Mahmood's proposals earlier this year, echoing Ms Rayner's criticisms.

The ex-Greater Manchester Mayor eventually ended up taking a more strident approach while campaigning in the Brexit-backing seat, vowing to cut migration further as Prime Minister.

Ms Mahmood is expected to water down her proposals ahead of Mr Burnham becoming Prime Minister.

The Home Secretary revealed earlier this week that some migrants may receive "special treatment" and be exempt from a settled status crackdown.

She highlighted the prospect of “transitional arrangements” for certain groups of people.

Ms Mahmood also suggested spouses and older people could be shielded from her plans to double the default qualifying time for permanent residency in the UK.

Mr Burnham, who was backed by 322 Labour MPs when nominations for the ongoing leadership race opened this week, sent a separate letter to his Commons colleagues about his vision.

“I want to create a different culture where MPs are happy and fulfilled doing their jobs, where everyone has a part to play and where opinions and approaches are respected, even where there’s difference,” Mr Burnham said.

“The Whips’ Office should be our HR department, not something to be feared or where discipline is used to stifle debate.”

The Makerfield MP added: “Politics hasn’t been good enough, but I know we can do better.

"Our Government will change the way the country is run: place first, not party first; problem solving, not point scoring."