RISHI Sunak has defended using Section 35 powers to block Scotland's gender reform bill.

The Prime Minister described the unprecedented move as a "bold" decision as he cited women's safety across the UK as the reason his government blocked the bill.

Sunak spoke on his 100th day in office during an interview with Piers Morgan on TalkTV.

During the programme, Morgan asked the PM to define what a woman is, claiming that other leaders such as Nicola Sturgeon have failed to answer the question.

Rishi said: “Of course I know what a woman is, an adult human female. What you’re actually asking when you ask that question is, I think, what’s my approach and view about how we as a society grapple with a situation where people are questioning or wanting to change their gender, their identity.

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Morgan then cited the recent cases of Isla Bryson and Tiffany Scott as he questioned the PM on self-identification.

The First Minister has urged people not to conflate the prison cases with Scotland's gender reform.

Sunak said the cases highlighted the issue with gender self-ID.

He said: "Now look first of all we must and should have enormous compassion and tolerance and understanding for those who are questioning their gender identity and wanting to change.

"We would always be supportive of that of course we will, and it is right to be compassionate about that. That's who we are as a people.

"But we have to recognise the challenges that that poses particularly for women's safety as we've just been discussing. That’s why biological sex really matters in women's spaces.”

Morgan then asked the PM: “When you see what's happening in sport, where you see trans women athletes demolishing women, female athletes, what do you feel about that?”

Rishi replied: “Well, I think that doesn’t strike most people as being fair, right? So that's why when it comes to these questions, biological sex matters.

"Now that, you know, we can and will have compassion and tolerance and understanding for everybody who is thinking about transitioning and changing their identity or gender.

"But you know, for me, when it comes to whether it's sex, whether it's women's spaces, whether it's prisons, biological sex really matters.

"And actually we saw that recently with what’s going on in Scotland and that's why I took, again, you say what else have you done in 100 days and what’s bold?

"We took action that hadn’t been taken before because the bill that was passed in Scotland, I think has real implications for how we think about these issues on a UK-wide basis and the interaction between these things, particularly on women’s safety.

"And that’s why I acted."

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Nicola Sturgeon has said it is likely that the UK Government will be taken to court over its decision to block the Gender Recognition Reform (Scotland) Bill.

The bill makes it easier for trans people to obtain a Gender Recognition Certificate (GRC). It also lowers the age a person can change their gender from 18 to 16.

Proponents say it will make what is currently a "degrading" and complicated process and simplify it to give transgender people dignity.

The Conservatives, along with some women's groups, have raised concerns about the impact the legislation could have on women-only spaces.