From a co-conspirator:

“I was in strangers bar last night and saw the fight first hand.

I don’t know who threw the first punch, or why it happened, but I first noticed something had happened when Conservative MP Alec Shelbrooke was trying to restrain Eric Joyce shouting “YOU DO NOT DO THAT TO AN MP IN THIS HOUSE!”. Others then tried to drag Eric away from everyone else.

Eric continued to struggle and broke away from those who were holding him back. A couple of people got punched, tables got knocked over, drinks spilt, and glasses broken. A Conservative female MP then put herself in between Eric and the people he was after shouting “PUNCH ME BEFORE YOU PUNCH MY STAFF!” Yet Eric continued to struggle.

A couple of people managed to hold him down on the ground until the police arrived, who cuffed him and took him away. The security informed us while they were taking statements and names that it took them so long to get there as they went to the Sports and Social bar first.”

Seems about right…