Student groups are to launch protests after the Oxford Union invited controversial historian David Irving and British National Party leader Nick Griffin to take part in a free speech forum.

OUSU President Martin McCluskey will chair an emergency meeting of sabbatical officers today, having vocally condemned the move to members of the Oxford University Labour Club on Wednesday night.

Both the National Union of Students (NUS) and the Union of Jewish Students have also promised to stage demonstrations if Irving and Griffin speak on 26 November.

Irving was imprisoned in Austria in 2006 for Holocaust denial, although at his trial he recanted his views, and is now absolutely without doubt that the Holocaust took place. Griffin has previously referred to the Holocaust as the "Holohoax".

Oxford Union President Luke Tryl said, "I can confirm that we have sent invitations and are in discussion with David Irving and Nick Griffin for our free speech forum on 26 November."

He defended his decision to invite them, saying, "It’s nothing to do with the Holocaust or racism. We always believe that we are the last bastion of free speech, and we want to explore where the limits of that lie through our forum.

"I expected OUSU to condemn this. I hope they’ll recognise that this isn’t being done because I sympathise with Irving or Griffin. I utterly condemn these people’s abhorrent views, but we are a debating society committed to free speech."

McCluskey claimed that any appearance would discredit the Union. "I find it utterly appalling," he said. "It sets a really disturbing precedent. The Union being a student run society, it sends out the wrong sort of message. All this is doing is giving them a platform in a prestigious arena.

"I think as a Union member it’s despicable that my membership fee and the membership fees of hundreds of freshers will be paying for hospitality for Holocaust deniers."

He added, "I’d want to know their reasoning as to why they were invited. It just seems to be courting controversy."

NUS President Gemma Tumelty promised that any appearance by Irving or Griffin would be strongly opposed.

"The Holocaust denier David Irving and leader of the fascist BNP Nick Griffin have no place in our multicultural society, let alone on our diverse university campuses. NUS utterly opposes racism and fascism wherever it arises and will certainly oppose any attempt by Oxford University’s debating society to invite Irving and Griffin to speak.

"We would condemn their presence on any campus and will certainly be active in campaigning to ensure that they are not given a platform at Oxford. Whenever we get confirmed information about his intended campus visit, NUS will act swiftly and severely," she said.

A spokesperson for the Union of Jewish Students (UJS) also attacked the Union’s decision to invite Irving and Griffin, and said that Irving and Griffin’s presence could be dangerous to certain minorities of students.

"We absolutely don’t approve of the speakers," he said. "Giving credibility to the Nick Griffins and David Irvings of this world has serious repercussions for Jewish students and other minorities. Where the BNP appear, we see a rise in racism, and that’s something the Oxford Union President should take into account.

The Union stated that Dr Evan Harris, Liberal Democrat MP for Oxford West and Abingdon, would also speak at the forum alongside author Anne Atkins and student debaters drawn from the Union’s members.

"I have agreed to debate the subject ‘This house believes that even extremists have a right to freedom of expression within the law’ at the Oxford Union," Dr Harris said. "It follows logically that I will not seek to support extremists by refusing to debate free speech with them.

"Extremist or offensive, but otherwise lawful speech should be ignored, ridiculed or argued against. It should not be shut down or driven underground. It is counter-productive to make free speech martyrs out of these people," he added.

In 2001, Union President Amy Harland cancelled a planned appearance by Irving after protests and fierce debate among the University community.

The University and College Union stated that the Union was repeating its previous error.

A spokesman said, "We have been here before when Irving was invited to speak in 2001. The outcry that followed ensured that invitation was withdrawn. We do not understand why seven years on, with Irving’s academic credentials far from enhanced, the Oxford Union wishes to repeat that mistake."In January 2007, Griffin was prevented from taking part in an Oxide Radio interview due to OUSU’s no-platform policy, which denies OUSU venues and services to those with fascist David Matthews