Sheffield Hallam MP Jared O'Mara has been suspended from the Labour Party amid an investigation over his "comments and behaviour".
The move follows public calls, from fellow Labour MPs and opponents, for Mr O'Mara's temporary expulsion from the party.
A string of Mr O'Mara's historical online comments emerged this week, together with new claims he used transphobic slurs and called a woman he dated an "ugly b****".
Confirming the party's action, Labour shadow chancellor John McDonnell said: "The decision has been taken to suspend Jared O'Mara and have the whip withdrawn because of that suspension.
"There will be a full investigation by the Labour Party and then, as a result of that, a final decision will be made about his future."
Mr O'Mara, who was elected to Parliament in June's snap General Election, had already resigned from the House of Commons' Women and Equalities Committee amid the row.
The 35-year-old described himself as "deeply ashamed" of his online comments and claimed he has been on a "journey of education" since making them.
He strenuously denies other claims he verbally abused a woman he met on a dating app earlier this year, branding the allegations "categorically untrue".
Sophie Evans claimed Mr O'Mara made offensive comments to her in March – just months before he was elected.
Describing how she met the politician before going on a date with him, but then decided it wasn't to be, Ms Evans told Sky News: "We were outside a club in Sheffield.
"He looked me up and down and said a lot of stuff that isn't repeatable but then called me an ugly b****.
"I was really annoyed when people were trying to defend him.
"Colleagues in the Labour Party saying it was a long time ago that he made the misogynistic and sexist comments.
"Well, the insults against me were this year – just months before he stood as an MP. I don't have any political affiliation but I don't think he is fit to be an MP."
She also claimed Mr O'Mara had used "transphobic slurs".
On Monday, Mr O'Mara was applauded by Mr Corbyn and other MPs for offering a "mea culpa" for comments made on an online forum between 2002 and 2004.
Among them were posts calling gay people "f****-packers" and suggesting singer Jamie Cullum should be raped to death with his own piano.
A senior Labour source told Sky News of Mr O'Mara's apology at a meeting of MPs: "He talked about his own experience as a young man, his own journey and his history as a disabled person.
"The room was silent while he was speaking. You could hear a pin drop."
Labour's Shadow Education Secretary Angela Rayner described the apology as "heartfelt".Let's