Boris Johnson has said that MPs should be selected “on their merits” as he refused to throw his backing behind all-female shortlists.

Speaking on Times Radio, the Prime Minister said selection processes would be left to local associations, adding that the Conservatives should be “incredibly proud” of promoting women in politics.

It comes after Tiverton and Honiton MP Neil Parish stepped down when he was named as the individual who had viewed pornography in the House of Commons chamber.

A by-election will be held in the Devonshire constituency to replace Mr Parish, who admitting to twice watching pornography in Parliament, saying he first accidentally viewed it after looking at tractors online before then acting deliberately.

Some Conservatives – including Caroline Nokes, the chairwoman of the Commons Women and Equalities Committee – want the party to ensure its candidate is a woman.

However, when questioned on whether he supported all-women shortlists, Mr Johnson said: “I’m very much in favour of people establishing their position, winning their position, on their merits.

“Women are doing absolutely brilliantly in the Conservative Party at the moment and we want to encourage it.”

In a nod to Home Secretary Priti Patel and Foreign Secretary Liz Truss, the Prime Minister noted that two of the four “top jobs in Government are currently held by women”.

While admitting that more needed to be done, Mr Johnson stressed that politics looked “very, very different” compared to when he first became an MP in 2001.

“We’ve come on in leaps and bounds,” he said. “Is there more progress to be made? Yes there is, and we’re making it.

“As for selection procedures, those are a matter for the local association.”

At the weekend, party chairman Oliver Dowden said he wanted the Conservatives to ensure more women MPs were elected so that the party in Parliament “reflects the wider country”.