A Labour MP today spoke of how he "wrestled" a man to the floor in "self defence" inside the Houses of Parliament.
Paul Farrelly, 48, described the altercation, that took place during a karaoke party at Parliament's Sports and Social Club, as "a John Prescott moment".
The MP for Newcastle-under-Lyme claimed he was confronted by a man in a corridor near the club at around 10pm on Thursday, after reprimanding him about his behaviour.
Mr Farrelly said today: "I acted in self defence and wrestled him to the ground to restrain him.
"It is not good to rise to provocation and you could call it a John Prescott moment if you like, but I was attacked and acted in self defence like any ordinary person would."
He said he did not originally speak out about the incident over fears it would make a "mountain" out of the situation.
"The man was behaving very badly inside and I had a word with him about his behaviour and he didn't like it," he said.
However, the Daily Mail today said the man, named in the paper as Bjorn Hurrell, 46, was likely to report the matter to police.
Friends of Mr Hurrell, who delivers newspapers in the Palace of Westminster and has had a full parliamentary pass for more than 20 years, told the paper he had been enjoying a karaoke night he helped his mother organise for Parliament's Sports and Social club.
They claimed Mr Farrelly had been drinking and entered with a group of people, before becoming involved in an altercation with Mr Hurrell at the bar.
It was reported that the MP had confronted him in a corridor outside the parliamentary bar.
Mr Farrelly today denied the claims, saying he had escorted a number of people to the club and was leaving when the incident occurred.
"It was complete self defence," he added.
"I was using the sports club but not attending the party and not in a large group - I was just talking to friends I hadn't seen for a long time.
"This man's behaviour by the bar was quite rude and I had a word with him and he clearly didn't like it. I acted in self defence."
The MP added he planned to speak to the social club's manager to explain what had happened.
Scotland Yard today said it had received no complaints about the incident.
Labour politician Mr Farrelly has been MP for Newcastle-under-Lyme since 2001. He served on the Science and Technology Select Committee until 2005, before becoming a member of the Culture, Media and Sports Select Committee.
He is a strong critic of anti-social behaviour telling constituents on his website: "Decent people should not see their lives blighted by nuisance and anti-social behaviour, nor should our children be led astray by a mindless minority.
"Working with key groups to identify underlying reasons and solutions for anti-social behaviour is helping make our local communities safer."