A Scottish Labour MP has stunned onlookers in the House of Commons after launching an unprovoked foul mouthed tirade against a political opponent.
East Renfrewshire MP Jim Murphy (pictured) lost control when SNP MP Pete Wishart appeared in the voting lobby as Mr Murphy and some of his Labour colleagues took part in a vote on the Bedroom Tax.
According to Mr Wishart, the Scottish Labour MP muttered something inaudible before going berserk, shouting and swearing at the nationalist MP.
Describing the episode, Mr Wishart said: "I was just taking a note of Scots Labour MPs who were voting in the bedroom tax motion after their famous failure to turn up last time. They didn't like it much but it was mainly banter with them as they came through the lobby.
According to the SNP MP, Mr Murphy muttered something as he went to walk past, to which Mr Wishart responded, 'nice to speak to you Jim'.
Explaining that neither men had spoken for years, the SNP MP added: "He then went beserk coming right up to my face and just repeating 'fuck off, fuck off, fuck off' at me.
"At one point I thought he might take a swing. He then retreated to a group of Labour MPs and I went up to ask him what that was all about? And he did the same again.
"I was angry and shaken and just asked him to say it again, in which he duly obliged."
Newsnet Scotland understands that a number of high profile Labour MPs witnessed the episode including Gordon Banks, Russell Brown, Ian Murray, Anne Begg and Fiona O'Donnel.
Wishart added: "They just watched on amazed."
The incident will be a major embarrassment for Mr Murphy who has repeatedly claimed to have been the victim of online abuse at the hands of independence supporters. Last December the Labour MP claimed to have been the victim of what he described as vile abuse at the hands of "cybernat trolls".
"If people want to criticise my politics, no bother. But I'm no longer just going to go with the flow when it comes to the worst of the internet insults," Murphy wrote on his own blog.
He added: "Politicians have got to have a thick skin and rightly be open to criticism; it’s part of the job and I have absolutely no problem with any and all political criticism. […] But enough is enough now when it comes to the personal poison devoid of any politics.
"No-one should be bullied out of their opinions nor right to speak. 2014 is going to be a gigantic year for Scotland and everyone who wants to be involved in the debate should be able to. And before anyone says 'all sides in all debates do it' I'm clear that it's wrong no matter where it comes from and no matter who it's aimed at.
"And I worry that folk who aren't currently involved in politics will be scared to do so for fear of getting screamed out of the referendum debate."
The incident comes almost two years to the day after one of Mr Murphy's collegues lost control in a House of Commons bar, lashing out at opposition MPs.
Eric Joyce MP was dragged away in handcuffs after going berserk in a House of Commons bar and headbutting a fellow MP. The Scottish Labour MP flew into a rage and hit at least three MPs, including a Labour whip. Joyce was later convicted of assault and resigned from the Labour party.