The Tories have sought to shore up their base since Prime Minister Rishi Sunak called the election two weeks ago, with the fringe right-wing Reform UK party threatening to eat into support.

Sunak has announced plans to bring back a form of national service for 18 year olds and greater protection for pensioners’ incomes if they are re-elected.

He has also been pushing the case for tough action on irregular migration and his party’s record on defence and security.

On gender identity, which has sparked furious debate, particularly in Britain’s right-wing media, Badenoch told LBC radio: “We want people to have privacy and dignity.

“This is about protecting those who are vulnerable, it is not about stopping trans people from having privacy and dignity,” she said.

“That’s why we have said you should have unisex toilets, a disabled toilet is an example of that, or where there are shared spaces, they should be on the basis of biological sex,” Badenoch added.

“Just putting on a different set of clothes does not make you transgender.”

Badenoch did not say what paperwork people might have to produce to prove their biological sex, when asked by BBC radio.

The opposition Labour party, which polls are predicting will win a thumping victory on July 4, has accused the Tories of stoking a culture war as a “distraction” from the issues on which voters look set to punish them.

“I think the government is failing on so many counts — time and again we have seen how it tries to wage these phony culture wars,” the deputy leader of the smaller opposition Liberal Democrats, Daisy Cooper, told LBC.