Protesters have stormed the Oxford Union throwing a planned debate featuring BNP leader Nick Griffin and controversial historian David Irving into disarray.
After pushing and shoving their way through the doors into the hall they staged a sit down protest at the debating table.
Scuffles erupted as the protesters tried to get into the building which had been surrounded by tight security ahead of Monday night's event.
Around 30 people sat in the debating hall singing protest songs until they were persuaded to leave.
The debate eventually went ahead more than a hour late with speakers split into two groups for safety. It was considered by university authorities to be too dangerous to walk Mr Griffin and Mr Irving across the quadrangle between the main Union building and the debating hall.
Instead Mr Irving, who was jailed for three years in Austria for denying the Holocaust, spoke alongside broadcaster and author Anne Atkins and Liberal Democrat MP Evan Harris in the debating hall while Mr Griffin was among debaters speaking in the main Union building.
Mr Harris said he was "disappointed" in the police response to the anti-fascist rally.
He criticised Thames Valley Police for "failing to put a cordon around the Union" and giving protestors the chance to storm in.
Nearly half of the students who had tickets for the event failed to get in after the crowd of around 500 outside the union blocked the gates.
Those who did make it in faced jeers of "shame on you".
