Rory Stewart said that while he served in Government there were "situations of male prisoners selfidentifying as females then raping staff in prison".

The former Tory MP, who ran in last year's leadership contest, made the remarks in GQ as he was interviewed as part of his candidacy for Mayor of London.

When asked whether anyone who identifies as a woman should be allowed to go into female-only spaces such as toilets, Mr Stewart said: “I’m instinctively worried about that, partly because when I was prisons minister, we had situations of male prisoners selfidentifying as females then raping staff in prison.

“So I think if someone is biologically male, particularly in an environment like a prison, we shouldn’t allow that to happen.

“We have to be pretty cautious about how we think that happens in other spaces.

“The important thing is: I think the rights of women to feel safe trump the rights of somebody who’s biologically male to enter that space.”