A senior Labour MP has apologised after a video emerged in which he made derogatory comments.
In the footage, which the Guido Fawkes website said was taken at an event held by the Jeremy Corbyn-supporting Momentum group, Clive Lewis, the former shadow business secretary, is heard to say: "Get on your knees, bitch."
A spokeswoman for the party said: "The Labour Party condemn the language used by Clive Lewis. It was completely unacceptable and falls far short of the standard we expect of Labour MPs."
Norwich South MP Mr Lewis said: "I apologise unreservedly for the language I used at an event in Brighton last month. It was offensive and unacceptable."
The video of Mr Lewis drew widespread criticism in Labour ranks, with former deputy party leader Harriet Harman tweeting: "Inexplicable. Inexcusable. Dismayed."
The chairwoman of the women's parliamentary Labour Party, Jess Phillips, also took to social media to express concern, tweeting: "Just seen the Clive Lewis video. Obviously I am appalled, just listened to 7 teenage girls speak up about gender inequality. Perhaps I'll bring them to work on Monday."
Former minister Yvette Cooper tweeted: "Agree w Jess. No excuse for saying this, whatever context."
Labour MP Stella Creasy branded the remarks unacceptable.
She tweeted: "It's not OK. Even if meant as a joke, reinforces menace that men have the physical power to force compliance."
Tory MP Mims Davies tweeted: "Astounding inappropriate language from @labourlewis I think @jessphillips needs to get you on an URGENT training course. This must stop."
A Momentum source said Mr Lewis made the comments to a male participant on stage who was kneeling down to take the score during a game show segment at an event, not to a female audience member.
Mr Lewis, who in the past has been spoken of as a future Labour leader, quit the frontbench earlier this year when he rebelled against Mr Corbyn and voted against triggering Brexit negotiations.