Shamed politician Eric Joyce has been arrested following a late-night brawl at a bar in the House of Commons, sources said.
The independent Member of Parliament for Falkirk was held after the incident at the Sports and Social Club bar.
A Metropolitan Police spokesman on Thursday said: "Police were called shortly before 10.30pm this evening to reports of a disturbance at a bar within the House of Commons.
"Officers attended and a man aged in his 50s was arrested in connection with this incident.
