Labour MP Eric Joyce has been charged with three counts of common assault following a fracas at a House of Commons bar, Scotland Yard said.
The former soldier, 51, was arrested at the Palace of Westminster on Wednesday night after officers were called to a disturbance at the Commons.
Mr Joyce, who was suspended from the Labour party following the incident, will appear on bail at West London Magistrates' Court on March 7, the Met said.
The MP for Falkirk spent around 24 hours in custody and was questioned over the late night disturbance. He was seen being driven away from the rear of Belgravia Police Station in central London in the back of a dark hatchback car at around 11.20pm following his release. The politician was wearing a white shirt and dark suit and appeared pale and unshaven.
Joyce was detained at around 10.50pm on Wednesday after claims he head-butted Conservative Stuart Andrew shortly before closing in the Strangers Bar, Parliament's pub for MPs.
Mr Andrew, MP for Pudsey, who has no visible cuts or bruises, responded to concerns about his welfare on Twitter by writing: "I'm ok."
Labour suspended Joyce from the party pending the results of the police investigation, branding the incident "extremely serious", though he remains an MP. Following his arrest a Labour Party spokesman said: "This is an extremely serious incident. We have suspended Eric Joyce pending the results of the police investigation."
Speculation about the incident has been rife in Westminster but Commons Speaker John Bercow thwarted any attempt to raise the matter in the chamber by issuing a stern warning at the start of proceedings. He told MPs: "I take this matter very seriously, as do the House authorities. I would ask that no further reference should be made to these reports in the Chamber."
Joyce, MP for Falkirk since December 2000, served in the Army Education Corps before pursuing a career in politics.
A Scotland Yard spokesman said: "Eric Joyce, aged 51, an MP of Union Street, Bo'ness, West Lothian, has been charged with three counts of common assault following an incident within the House of Commons on Wednesday, 22 February. He will appear on bail at West London Magistrates' Court on 7 March."