Labour MP Eric Joyce was suspended from the party today following allegations that he assaulted a fellow MP in a House of Commons bar on Wednesday night.
Mr Joyce reportedly headbutted and punched Stuart Andrew, Tory MP for Pudsey in West Yorkshire, in the Strangers Bar - a Commons drinking den reserved for MPs and their guests
Scotland Yard confirmed that officers detained a man in his fifties after being called to reports of an incident at a bar within the Palace of Westminster at around 10.50pm.
He was taken into custody at a central London police station.
Mr Joyce has represented Falkirk since December 2000 after serving in the army and a stint at the Commission for Racial Equality.
A Labour spokesman said: "This is an extremely serious incident. We have suspended Eric Joyce pending the results of the police investigation."
Mr Joyce hasn't been kicked out of the Commons, but he cannot take the Labour whip until the investigation is concluded.
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