A Labour MP who joked about having an orgy with members of the pop group Girls Aloud has resigned from his position on the Women and Equalities select committee.

Jared O'Mara earlier apologised for the offensive comments, which emerged in a report by website Guido Fawkes, but by the evening his office confirmed that he had also quit his select committee role.

"He has decided to stand down. He has made that decision," a spokesman for the MP said.

As well as comments about Girls Aloud, Mr O'Mara had claimed Michelle McManus only won Pop Idol "because she was fat" and suggested it would be funny if jazz star Jamie Cullum was "sodomised with his own piano".

Other remarks on online message boards attributed to Mr O'Mara include the use of derogatory terms about gay people, Guido Fawkes reported.

Mr O'Mara, who ousted former deputy prime minister Nick Clegg in the June election to become MP for Sheffield Hallam, made the comments in 2004.

In his apology earlier, Mr O'Mara said: