David Cameron has accused Labour of allowing people with “bigoted religious views” to organise political meetings where men and women are segregated.

There have been several reports of Labour politicians addressing meetings where men and women are segregated – in Birmingham last May and during the Oldham byelection campaign in December. The party has always denied allowing meetings to be organised in this way.

One general election meeting in Birmingham addressed by Tom Watson and four other Labour MPs was reportedly advertised to local Muslim communities as having a “women’s section”, and a sign was said to have directed female attendees to separate seats.

Cameron raised the issue during prime minister’s questions on Wednesday, in response to a Labour MP asking about cuts to benefits for women. He said the opposition’s contribution to gender equality should be to stop allowing political meetings to be segregated for religious or cultural reasons.

To loud Conservative cheers, he said: “Let me say this to the Labour party, one thing you could help with: no more segregated political meetings. Let us end the process of having people with bigoted religious views treating women as second-class citizens. I think you should all take a pledge: no more segregated meetings.”

He was backed by Stephen Crabb, the Welsh secretary, who said: “Requiring men and women to sit apart is an affront to British values.”

A Labour spokesman again denied that any segregation had taken place. “The Labour party organises no segregated meetings, and segregated meetings are wholly unacceptable,” he said. “If it has happened, then we’ll have to investigate, and tackle that.”