The new work and pensions secretary is facing calls to urgently review the “rape clause” in child tax credits.
A cap came into force in April where a parent could only claim the credit for two children, but if they had another by “non-consensual conception” they would be exempt – if they filled out the correct paperwork.
Former Scottish Labour leader Kezia Dugdale says the policy is “degrading”.
But the department said its methods were as “sensitive as possible”.
The policy to cap child tax credit was announced in 2015 by then-Chancellor George Osborne.
The UK government said it had introduced the limit, for a claimant’s first two children, because it wanted “people on benefits to make the same choices as those supporting themselves solely through work”.
Exemptions were announced for those adopting children, those involved in kinship care and for multiple births, as well as those who had a child conceived “as a result of a sexual act which you didn’t or couldn’t consent to” or “at a time when you were in an abusive relationship, under ongoing control or coercion by the other parent of the child”.
The Department for Work and Pensions (DWP) said it would operate a “third-party model” so that women could talk to healthcare professionals, a social worker or an approved rape charity, rather than describe the details to a member of its staff.
But critics say the policy forces victims of rape to endure further trauma, making women “prove” they have been raped to receive child benefits.
In a letter to the minister, Ms Dugdale – who has campaigned against reducing the welfare state – quoted Ms McVey’s previous statements supporting feminism and said she should “take this sentiment into office”.
“I consider [the rape clause] to be one of the most abhorrent policies of a government in my adult lifetime,” she wrote.
“It essentially punishes a woman for being the victim of a violent act at the hands of a man – a punishment which will be felt by the product of that violence, which in the context of the rape clause is a child.”
Ms Dugdale, who has campaigned against the policy with members from across different parties in the Scottish government, told BBC Radio 5 Live that while she accepted she held different political views to Ms McVey, perhaps they could agree “as women” that this clause was wrong.
“This isn’t rhetoric from a Labour politician throwing it at a Conservative politician and the back and forth you would normally expect from that,” she said.
“I am appealing to Esther McVey as a woman to repeal the rape clause as the first thing she does as secretary of state.”
Ms McVey is the first female work and pensions secretary since the Conservatives took office in 2010.
She has yet to respond personally to the letter.
However, a spokeswoman from the Department for Work and Pensions said they had consulted widely on the policy and had ensured that women who face these “very difficult circumstances” are exempt.
She added: “Using third-party professionals, who already support women in circumstances such as these, means the exception can be applied as sensitively as possible.”