One of the busiest bars in Parliament has closed after a staffer allegedly glassed another in the face leaving him with serious injuries.
The two men had reportedly stepped outside following a row.
Police were called to a courtyard near the Sports and Social Club Bar at 6.30pm on Tuesday after an altercation.
They arrested one of the men, aged 57, on suspicion of causing grievous bodily harm and affray.
The other man, 64, was taken to hospital in an ambulance for treatment for non-life threatening injuries, Scotland Yard said.
No other people were involved and officers from Westminster are investigating the incident.
A House of Lords spokesman said: ‘Following an incident on the parliamentary estate last night involving two parliamentary staff, after leaving the Sports and Social Club Bar, an investigation is under way and the bar will be temporarily closed until that investigation is complete.’
Former MP Eric Joyce was arrested on suspicion of assault in 2013 after a brawl at the bar.