Labour MP Vicky Foxcroft has resigned as a whip over the government’s plans to cut disability benefits.
In a letter to the prime minister, Foxcroft said she understood the need to address “the ever-increasing welfare bill” but said cuts to personal independence payments and universal credit should “not be part of the solution”.
She said she had “wrestled with whether I should resign or remain in the government and fight for changes from within”.
She added: “Sadly it now seems that we are not going to get the changes I desperately wanted to see.”
She said she would not be able to vote for the Universal Credit and Personal Independence Payment Bill, which will be debated in Parliament on 1 July.
More than 100 Labour MPs have expressed concern about the bill and government could face a large rebellion from its own backbenchers when it comes to a vote.
Earlier this week, Prime Minister Sir Keir Starmer reiterated his belief in the proposed legislation telling reporters: “We have got to get the reforms through.”
Ministers have argued that claimant levels are rising to unsustainable levels, and figures released this Tuesday said the numbers of people on personal independence payments had reached a record high of 3.7m.
The bill, published earlier this week, confirmed the government’s plans to tighten the criteria people have to meet in order to get Pips and cut the sickness-related element of universal credit.
On Wednesday impact assessment said the government expected 370,000 existing claimants in England, Wales and Northern Ireland to lose out, saving £1.7bn by 2029/30.
A further £1.89bn could be saved from a predicted 430,000 drop in the number of potential future claimants.
Another impact assessment, published in March suggested 250,000 people could be pushed into poverty but the cuts – but ministers said the figure didn’t take account of the £1bn it would spend to help the long-term sick and disabled find work.
As a government whip, Foxcroft would have been expected to persuade reluctant Labour MPs to back the proposed legislation.
The Lewisham North MP said she was quitting because she knew she would “not be able to do the job that is required of me and whip – or indeed vote – for reforms which include cuts to disabled people’s finances”.
She added that she was “incredibly proud to have served as part of the first Labour government in 14 years and hope that ministers will revisit these reforms so that I can continue to support the government in delivering for the people of this country”.
Foxcroft was first elected to her south London constituency in May 2015.