UPDATED: The Labour Party has suspended MP Jared O'Mara after his misogynistic and homophobic comments online. More to follow.

ABUSIVE comments allegedly made by under-fire Labour MP Jared O’Mara to a constituent are “unacceptable” and could trigger an internal investigation, shadow chancellor John McDonnell said.

O’Mara “categorically denies” the claim he called his Sheffield Hallam constituent Sophie Evans an “ugly bitch” just months before his election.

O’Mara resigned from his position on the Commons Women and Equalities Committee on Monday in a row over homophobic and sexist online comments posted more than a decade ago.

Newly revealed online comments from the same period show that he also made derogatory remarks about Spanish and Danish people.

Labour leader Jeremy Corbyn faced calls to remove the whip from O’Mara following the latest claims about his behaviour.

The MP won the Sheffield Hallam seat in June, ousting former deputy prime minister Nick Clegg.

Evans said that some of the comments made to her by O’Mara in March this year “aren’t broadcastable”.

“There were some transphobic slurs in there, but he called me an ugly bitch,” she said.

“I just thought ‘wow, he’s not a very nice man’ and just forgot about it.

"I knew that he was involved in politics but I had no idea at the time he was running for MP for Sheffield Hallam, which is my constituency.”

She added: “I just kind of thought that someone like that couldn’t possibly be that heavily involved.”

Evans dismissed O’Mara’s claims that he had changed in the years since his online posts, which dated to the early 2000s.

She said: “Fair enough for him to have said that about 15 years ago, but he won’t even acknowledge something that happened seven months ago.”

A spokesman for O’Mara said: “He categorically denies the latest allegations.”

McDonnell said: “He has apologised for what we knew yesterday. He issued a profuse apology. Any language like that we know is unacceptable and I’m hoping he will apologise for that.”

Asked if there should be an investigation, McDonnell said: “That would be the normal process.”

In an interview with a magazine, O’Mara said he had made a “full and unreserved” apology to Labour MPs about the online remarks and felt “deeply ashamed” of his past comments.

Asked if he should quit Parliament, he said: “In terms of resigning as an MP? I think there’s a place for me ... I want to educate people and help people going through those prejudices grow out of them.

“I’ve gone on that journey and feel I can help. If a Conservative MP had made similar comments, I’d say it depends on what journey they had been on since. If they’d honestly changed and believed in equality and egalitarianism then absolutely [they have a place in Parliament], but the very culture of conservatism doesn’t foster that equality.”

Shadow women and equalities minister Dawn Butler said: “It’s not acceptable and it’s completely offensive language.

“I’m pleased that Jared has gone on a journey – I think he has probably got further to go on his journey.”