Labour MP Vicky Foxcroft has resigned as a Government whip over proposed benefit cuts. In a letter to the Prime Minister, the MP for Lewisham North said she understood "the need to address the ever-increasing welfare bill" but did not believe the planned changes "should be part of the solution".
She said: "I have wrestled with whether I should resign or remain in the Government and fight for change from within. Sadly it is now seems that we are not going to get the changes I desperately wanted to see.
"I therefore tender my resignation as I know I will 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."
Sir Keir Starmer has faced a backlash from some Labour MPs over proposals to reform the welfare system expected to save up to £5 billion a year.
Ms Foxcroft, who previously served as shadow minister for disabled people, is the first frontbencher to resign over the row.
Her exit comes after legislation introduced into Parliament yesterday includes a tightening of the criteria for the main disability payment in England, personal independence payment (Pip).
Ministers also want to cut the sickness related element of universal credit (UC), and delay access to it, so only those aged 22 and over can claim it.
The package of reforms is aimed at encouraging more people off sickness benefits and into work in a bid to get a grip on the ballooning benefits bill.
But dozens of Labour rebels last month warned that the proposals were "impossible to support".