Labour splits over plans to slash billions of pounds from the welfare bill have erupted after Andy Burnham became the latest senior party figure to voice his concerns.
The Manchester mayor said there was “no case in any scenario for cutting the support available to disabled people who are unable to work”.
Work and pensions secretary Liz Kendall will unveil the government package of reforms on Tuesday as she tries to cut £6 billion from the benefits bill.
Ministers say the current benefits system traps people on welfare instead of helping them get back to work.
It is understood the government has ditched plans to impose a freeze on Personal Independence Payments, which are made to disabled people, following a wave of criticism from campaigners and MPs.
However, the eligibility criteria for deciding who should receive that benefit could still be made more strict to reduce the numbers claiming it.
Other potential changes include changes to Universal Credit, which couldsee the amount paid to those deemed too ill to work reduced.
Writing in The Times, Burnham said he agreed that the welfare system needed “a radical overhaul”, but said the government should focus on helping people into work rather than simply cutting benefits.
He said: “I would share concerns about changing support and eligibility to benefits while leaving the top-down system broadly in place. It would trap too many people in poverty.
“And to be clear: there is no case in any scenario for cutting the support available to disabled people who are unable to work.”
As many as 80 Labour MPs - including some ministers - could vote against the welfare cuts when they come before the House of Commons.
One of the rebels, Richard Burgon, told HuffPost UK: “This isn’t what Labour people got into politics to do.
“Labour MPs feel that the government needs to think again. A Labour government should not be punishing the poorest or the most vulnerable.”
But appearing on the BBC yesterday, health secretary Wes Streeting said: “We don’t want to take money from the poorest in society, we want to support people who are the poorest and most vulnerable to make sure they’ve got dignity, independence and great quality of life.”