The Welsh Secretary has been asked if she will resign if benefit cuts are announced, after she broke the Labour whip a decade ago to vote against similar changes while in opposition.

Plaid Cymru’s Westminster leader Liz Saville Roberts (Dwyfor Meirionnydd) said she had voted alongside Jo Stevens in opposition to Conservative government policy in 2015.

Ms Stevens defied Labour Party directions to abstain on the vote on the Welfare Reform and Work Bill in the aftermath of that year’s general election.

The order by interim leader Harriet Harman lit the touchpaper on the then-Labour leadership contest. It helped propel Jeremy Corbyn, who also voted against the cuts, to the party’s leadership.

Plaid Cymru MP Liz Saville Roberts questioned Jo Stevens (Ian West/PA)

Ms Saville Roberts said: “Back in 2015, the Secretary of State and I walked through the same voting lobby against what she then described as ‘despicable Tory welfare cuts’, and she dared to break the Labour whip to do so back then.

“Given this evidence of her strong convictions on the issue, how can she justify remaining in a Cabinet intent on implementing Tory-style welfare cuts?”

Earlier this week, Sir Keir Starmer said the Government could not “shrug our shoulders and look away” over reforms being considered for the welfare system. The overall bill is projected to reach £70 billion by 2023.

Changes could be announced by Chancellor Rachel Reeves in the spring statement on March 26.

Charities, including the MS Society, mental health charity Mind and foodbank organisation the Trussell Trust have written to Ms Reeves urging her to “think again” about cuts.

They said analysis by Scope suggested 700,000 disabled households “could be pushed into poverty” without Personal Independence Payments (PIP).

Work and Pensions Secretary Liz Kendall has said there are 2.8 million people not in work due to ill health and one in eight young people not in education, training or employment.

The sickness and disability bill for working-age people has risen by £20 billion since the pandemic.

Ms Kendall has said an upcoming Health and Disability Green Paper will set out plans to support those who can work back into jobs, rather than write them off.

Ms Stevens said: “We have inherited a Tory welfare system that is the worst of all worlds.

“It has got the wrong incentives, it discourages people from working, the people who really need a safety net are still not getting the support that they need, and the taxpayer is funding an ever-spiralling bill.

“It’s unsustainable, it’s indefensible and it’s unfair. Our principles for reform are clear, supporting those who need support, restoring trust and fairness in the system, fixing that broken assessment process and disincentives, and supporting people to start, stay and succeed in work. She should support that as well.”

At Prime Minister’s Questions on Wednesday, Sir Keir said one in eight young people were not in education, work or training.

Sir Keir said he understood the fears of disabled people, and their families and friends over the cuts.

He said: “I come from a family that dealt with a disability through my mother and brother over many years, so I do understand the concerns that have been raised by him, but we inherited a system which is broken, it is indefensible, economically and morally, and we must and we will reform it.

“We will have clear principles, we will protect those who need protecting. We will also support those who can work, back to work, but Labour is the party of work, we’re also the party of equality and fairness.”