First Minister Nicola Sturgeon woos the women of New York during meeting with Hillary Clinton

The First Minister was speaking at the Women In The World summit, organised by journalist Tina Brown, when she criticised May for the policy during a question on women in politics.

There were audible gasps from the two and half thousand people squeezed into the David H. Koch Theatre in New York’s Lincoln Centre, as the SNP leader spelled out the changes to the UK’s benefit policy that came into effect on Thursday.

Though it was great Labour and the Tories in Scotland were led by women, the First Minister said, that did not mean Scotland had “every problem around gender equality solved”.

“It’s not enough to be a woman in a leadership position,” Sturgeon argued, “it’s important that you do the right things with it.

“There’s a policy that took effect in the UK today and, I have to apologise because I get angry and upset just talking about this, there’s a policy introduced in the UK today, it’s become known as the rape clause.

“We have a system of tax credits, the state support for low income families. This new law only allows women to claim tax credits for two children. For a third or subsequent child, if they claim or are to be eligible for tax credits, they have to prove that the child was conceived as a result of rape.

“It is a disgusting and disgraceful policy, but that policy has been introduced by a woman prime minister.

“That’s the point I’m making; It’s not enough to be a woman in politics, you have to do the right things with the power you’ve got.”

The Tories defended the policy on Thursday saying: “We believe women who have been raped and, as a consequence, have a child should be granted an exemption from these benefit restrictions.

“That’s exactly what this measure does in the most sensitive way possible.”

That defence prompted a furious reaction.

Sturgeon was appearing at the conference on the second last day of her trip to the States. She was speaking ahead of Hillary Clinton, who was giving her first interview since losing the US presidential election to Donald Trump.

Though most of the audience were there to see the former Secretary of State, the First Minister made an impression, with Nicola Sturgeon becoming a top trend on Twitter in New York.

The two women met backstage and chatted briefly and posed for photographs. During her interview Sturgeon had said female politicians like her owed Clinton “a debt of gratitude”.

“The way that Hillary was talked about, the treatment that Hillary suffered at times, just seemed to me to have an air of misogyny about it, that I wanted to believe that we had moved on from,” she said.

“I look at Hillary and she has been a trailblazer for women in politics, whatever you think about her politics.

“I find many of her qualities are admirable. Her sheer resilience I find utterly amazing,She has made it easier for women like me in politics and I think for that I and women across the world really owe Hillary Clinton a debt of gratitude,”

On President Trump, Sturgeon said she hopes to “find areas of agreement with the Trump administration.” But also praised Angela Merkel and others for speaking out against the half-Scottish tycoon in the Whitehouse, and for refusing to “maintain a diplomatic silence” when “fundamental principles” are at stake.

The First Minister, was also pressed on the Daily Mail’s now infamous “Never mind Brexit, who won Legs-it!” front page, where the newspaper focused more on the legs of May and Sturgeon, than on the policies being discussed.

“I tried not to overreact,”Sturgeon said. “No matter how much progress women have made and are making, it’s a vivid illustration of how much more we still have to achieve,” she said.

She added: “This tendency to reduce women to body parts or to what they wear or what their hair looks like is not innocent and it’s not something we should just laugh off,” she said.

Sturgeon was also asked about her recent decision to talk publicly about the miscarriage she suffered in 2011.

In December last year, the SNP leader told the author of a book about SNP leaders that she and husband Peter Murrell had lost a baby in the early stages of pregnancy when she was deputy First Minister.

She told the audience “It wasn’t a decision I took lightly, but I decided to speak out about it because it’s one example of a position I’m in to change the attitude toward certain things.”

“Assumptions were made about why I didn’t have children,” she said. One of those assumptions was that she had made a “cold and calculated” decision to pursue a political career rather than have kids.

“There’s absolutely nothing wrong with a woman deciding not to have children,” she said.

“I decided to speak out my experience of having a miscarriage to challenge some of those assumptions. If I can do anything to make it easier for women in the next generations of politics…then I think I have a responsibility.”

She also pointed out that while she has been asked often why she doesn’t have children, Alex Salmond, who also has no offspring, has never been asked that question.

Brown, who founded the event, called Clinton and Sturgeon, the “two women I admire most anywhere”.