HYNDBURN MP Graham Jones said he witnessed an alleged assault in a House of Commons bar on Wednesday night.
Police said they arrested a man in his 50s following allegations of an incident in the Strangers Bar, which is reserved for MPs and their guests.
It is understood the man is Falkirk MP Eric Joyce, who was yesterday suspended by the Labour Party.
Stuart Andrew, Tory MP for Pudsey, West Yorkshire, has alleged he was the victim of an assault.
Mr Jones, who was back in Lancashire yesterday to attend a county council meeting, said he witnessed the alleged incident.
He said: “The matter is in the hands of police. so I do not want to say anything that might skew justice.
“The police haven’t contacted me to make a statement, but if they do I will be more than happy to do so.”