Sir Keir Starmer has been forced to climb down over Labour welfare cuts to avoid a humiliating Commons defeat next week.
Disabled people who currently receive the personal independence payment (PIP) will continue to do so after the Government made concessions to Labour rebels on the controversial reforms.
A letter from Work and Pensions Secretary Liz Kendall to MPs reveals that adjustments to universal credit would also see incomes protected.
The announcement comes after crisis talks with backbenchers, with some 126 MPs within the party signing an amendment that would halt the legislation in its tracks.
Sir Keir Starmerâs Universal Credit and Personal Independence Payment Bill has its second reading on Tuesday, the first opportunity for MPs to support or reject it.
A spokesperson for Number 10 said: âWe have listened to MPs who support the principle of reform but are worried about the pace of change for those already supported by the system.
âThis package will preserve the social security system for those who need it by putting it on a sustainable footing, provide dignity for those unable to work, supports those who can and reduce anxiety for those currently in the system.
âOur reforms are underpinned by Labour values and our determination to deliver the change the country voted for last year.â
The Governmentâs original package restricted eligibility for PIPs, the main disability payment in England, and limited the sickness-related element of universal credit.
Existing claimants were to be given a 13-week phase-out period of financial support in an earlier move that was seen as a bid to head off opposition by aiming to soften the impact of the changes.
The proposed cuts aimed to save ÂŁ5billion a year by 2030, with working-age health-related benefit spending expected to rise from ÂŁ52bn in 2024 to more than ÂŁ66bn without any changes to the system.
The U-turn on PIPs for around 370,000 existing claimants will cost the government at least ÂŁ1.5bn, according to the Institute for Fiscal Studies.
In her letter, the Work and Pensions Secretary said: âWe recognise the proposed changes have been a source of uncertainty and anxiety.
âWe will ensure that all of those currently receiving PIP will stay within the current system. The new eligibility requirements will be implemented from November 2026 for new claims only.
âSecondly, we will adjust the pathway of Universal Credit payment rates to make sure all existing recipients of the UC health element â and any new claimant meeting the severe conditions criteria â have their incomes fully protected in real terms.â
She said a ministerial review would ensure the benefit is âfair and fit for the futureâ and will be a âcoproductionâ with disabled people, organisations which represent them and MPs.
âThese important reforms are rooted in Labour values, and we want to get them right,â she said.
The change in PIP payments would protect some 370,000 existing claimants who were expected to lose out following reassessment.
If the legislation clears its first hurdle on Tuesday, it will then face a few hoursâ examination by all MPs the following week â rather than days or weeks in front of a committee tasked with looking at the Bill.
The so-called âreasoned amendmentâ tabled by Treasury select committee chairwoman Dame Meg Hillier had argued that disabled people have not been properly consulted and further scrutiny of the changes is needed.
She said: âThis is a good deal. It is massive changes to ensure the most vulnerable people are protected⊠and, crucially, involving disabled people themselves in the design of future benefit changes.â
While the concessions look set to reassure some of those who had been leading the rebellion, other MPs remained opposed before the announcement.
Speaking to the PA news agency before the concessions were revealed, Rachel Maskell said: âAs the Government is seeking to reform the system, they should protect all disabled people until they have completed their co-produced consultation and co-produced implementation.
âI cannot vote for something that will have such a significant impact ⊠as disabled people are not involved, it is just a backroom deal.â
One MP said that ministers would need to âgo back to the drawing boardâ to make the Bill acceptable.
Another said they expected the legislation would get through second reading if the Government conceded the key sticking points relating to existing Pip claimants, the health element of universal credit and a policy consultation.
âIt would need to be in the Bill, not just a commitment,â they said.
Speaking in the Commons on Wednesday, Sir Keir told MPs he wanted the reforms to reflect âLabour values of fairnessâ and that discussions about the changes would continue over the coming days.
He insisted there was âconsensus across the House on the urgent need for reformâ of the âbrokenâ welfare system.
âI know colleagues across the House are eager to start fixing that, and so am I, and that all colleagues want to get this right, and so do I,â he said.
âWe want to see reform implemented with Labour values of fairness.
âThat conversation will continue in the coming days, so we can begin making change together on Tuesday.â
There was a mixed reaction among charities to the prospect of concessions. Learning disability charity Mencap said the news would be a âhuge relief to thousands of people living in fear of what the future holdsâ.
âIt is the right thing to do and sends a clear message â cutting disability benefits is not a fair way to mend the black hole in the public purse,â director of strategy Jackie OâSullivan said.
But the MS Society urged rebels to hold firm and block the Bill, insisting any Government offer to water down the reforms would amount to âkicking the can down the road and delaying an inevitable disasterâ.
Head of campaigns at the charity, Charlotte Gill, said: âWe urge MPs not to be swayed by these last-ditch attempts to force through a harmful Bill with supposed concessions.
âThe only way to avoid a catastrophe today and in the future is to stop the cuts altogether by halting the Bill in its tracks.â
The Tories described concessions as âthe latest in a growing list of screeching U-turnsâ from the Government.
Shadow chancellor Mel Stride said: âUnder pressure from his own MPs, Starmer has made another completely unfunded spending commitment.
âLabourâs welfare chaos will cost hardworking taxpayers.
âWe canât afford Labour.â