One of the BBC’s most popular quiz shows on Radio 4 has been found guilty of anti-Tory bias after broadcasting a joke attacking the Prime Minister Theresa May.

Scottish comedian Susan Calman, 43, a regular on The News Quiz comedy panel show violated the BBC’s own “impartiality” rules on the episode broadcast in June.

She attacked Mrs May as a “coward” for not pushing the people of Northern Ireland to legalise abortion, claiming the Prime Minister was scared of the province’s largest elected group the Democratic Unionist Party, which opposes abortion.

According to The Times, she said: “There’s been a lot of chat about if Theresa May’s a feminist she needs to step in. This is not a feminist issue. You don’t need to be a feminist to say that women should have equal rights.”

Adding: “What she is, is a coward. And unless she steps in, that is one part of the United Kingdom where not only gay people but also women don’t have the same rights as other parts of the United Kingdom.”

Delighted to announce a new show for BBC 2 Scotland, Susan Calman’s Fringe Benefits. Coming smack bang in the middle of this year’s Fringe, I’m hosting my very own TV comedy spectacular, it’ll be the best place to catch all the funniest comedy from this year’s festival.More soon! pic.twitter.com/dfzCTazFhp — Susan Calman (@SusanCalman) June 12, 2018

BBC panel shows, particularly in comedy, frequently feature more left-wingers that those on the political right, with frequent claims of political bias.

The episode was broadcast just after the Republic of Ireland voted to overturn its abortion ban and senior executives reportedly rebuked producers on the quiz show for breaking impartiality rules.

A BBC spokesman said: “Our comedy programmes have a long history of panellists making satirical comments aimed at politicians from across the spectrum.

“Clearly, the expectations around impartiality in a comedy series are different to a news programme, and audiences don’t tend to turn to comedy as a political guide.

“Expression of a personal and political view is not a breach of the BBC’s editorial guidelines but they require all programmes to show due impartiality especially when dealing with topical, controversial issues.”