MP Simon Danczuk has apologised "unreservedly" for "inappropriate" behaviour after being suspended from the Labour Party for sending sexually explicit messages to a teenage girl.
An investigation is being launched by the party's ruling body after claims that the backbencher bombarded Sophena Houlihan with lewd texts when she was 17.
Mr Danczuk, 49, said the reports in The Sun were "not entirely accurate" but issued an apology and admitted "there's no fool like an old fool".
The teenager, who is now 18, said the Rochdale MP sent her numerous messages, including one asking if she wanted a "spanking" after she contacted him about a job.
She told the newspaper: "When I first got in touch I never expected the messages to get so graphic. At the time I played along with it, but now I feel like he duped me.
"I was keen for a career in politics and he is a very high-profile MP and I was in awe of him."
Mr Danczuk and the teenager exchanged messages for nearly a month before he asked how old she was, according to the newspaper.
The MP's personal life has repeatedly made the headlines over the past year following the collapse of his marriage to wife Karen, who was dubbed the selfie queen after posting numerous photographs of herself in low-cut tops.
Mr Danczuk said his work to expose child sex abuse had left him depressed and helped to cause the split. He revealed he was receiving psychiatric treatment and would be stepping back from his campaigning.
He embarked on a very public relationship with a Labour councillor, Claire Hamilton, who tweeted after Christmas that she had "dumped" Mr Danczuk.
He said the episode with Miss Houlihan came when he was at an "extremely low point in my life".
He tweeted: "My behaviour was inappropriate & I apologise unreservedly to everyone I've let down. I was stupid & there's no fool like an old fool."
Labour leader Jeremy Corbyn said the decision over Mr Danczuk's future rests with the party's National Executive Committee, which is investigating the allegations.
During a visit to York, Mr Corbyn said: "There will now be an independent investigation. He will make his case to that investigation.
"The concerns that have been raised will be discussed with him and a decision will be reached. But that will be independent, it will not be down to me or any other individual to decide what happens."
Ken Livingstone, who is on Labour's NEC, said the claims were "really disturbing".
"I just find it so bizarre because he put himself at the centre of the investigation into sex abuse of young girls in his area and so on," he told LBC.
Mr Livingstone said suspending people had been "very rare" when he first sat on the NEC but had "almost become an industry now" within the Labour Party.
Conservative MPs claimed the suspension was down to Mr Danczuk's outspoken attacks on the Labour leader.
Michael Fabricant tweeted: "Stupid, @SimonDanczuk may have been, but has he broken any law? Would he have lost #Labour membership if he hadn't been a critic of #Corbyn?"
Stewart Jackson tweeted: "Simon Danczuk has obviously been foolish but he's also been stitched up like a kipper by the Corbyn cronies in @UKLabour.
"Given he's had some mental health issues, more compassionate thing would to have given him space & return to the issue next week."
A Labour spokesman said: "The general secretary of the Labour Party has today suspended Simon Danczuk's membership of the party, pending an investigation into allegations published in the media today.
"A full investigation will now take place under the authority of the National Executive Committee, which will be responsible for determining any further action."