Eric Joyce, a Labour MP, was suspended by his party as police investigated an incident in which he is alleged to have head-butted a Conservative MP during a late-night fracas in a House of Commons bar.
The 51-year-old MP for Falkirk spent the night at Belgravia Police Station, where he was questioned after Stuart Andrew, Tory MP for Pudsey, said he wanted to press assault charges.
Among ministers, MPs and Commons officials there was only one talking point yesterday – and it wasn't Nick Clegg's plans for House of Lords reform. "There was a bloodbath," one senior Conservative reported.
Another MP said breathlessly: "It was like the Wild West."
Inevitably, there were slightly differing accounts about what happened in the wood-panelled Stranger's Bar at about 10.50pm on Wednesday. The common factor was that former Army Major Mr Joyce "exploded", apparently without reason. Some said that, after entering the bar at about 10pm, he was singing songs and the trigger came when another MP asked him politely to turn down the volume a little. Another version was that he became upset when someone moved a bar stool.
One source said: "He just flipped. It was not really a brawl or a fight. He just started lashing out."
Witnesses heard Mr Joyce shout: "There are too many f***ing Tories in here." Then Mr Andrew, having a quiet pint of beer, was allegedly headbutted by the Falkirk MP. One colleague described him as "an innocent victim" who happened to be sitting in "the wrong place at the wrong time".
Police were called and Mr Joyce was handcuffed, but was reportedly still struggling as he was led away. A glass window in the corridor was broken.