It styles itself as the world's most prestigious debating forum, a hallowed chamber at the heart of Oxford University that has played host, over the years, to everyone from Mother Teresa to Henry Kissinger, and from Diego Maradona to the Dalai Lama.
But now the Oxford Union is courting furious controversy for inviting two guests of an altogether different distinction. David Irving is a discredited historian who served a year in an Austrian jail for denying the Holocaust. Nick Griffin is leader of the far-right British National Party (BNP), who was convicted nine years ago for incitement to racial hatred for publishing material that denied the Holocaust
Invitations to the pair to take part in a debate on Monday night has provoked furious reaction in Britain. MPs and ministers have withdrawn from events or resigned their membership of what is essentially an elite club for the political leaders of tomorrow to cut their teeth.
Antifascist groups were descending on Oxford Sunday to vent their anger at the decision to offer a platform to two of Britain's most venomous voices on the right.
"This is not about freedom of speech, it's about providing a free platform to disseminate fear in the British community of Jews, Asians, and black people," says Denis MacShane, a Labour MP and former minister, who pulled out of an Oxford debate because of the invitation.
Mr. Irving and Mr. Griffin, he says, "have had freedom of speech. They have had their day in court and were convicted of Holocaust denial which is one of most egregious forms of anti-Semitism."
Mr. MacShane is not the only one voting with his feet. Last week, the defense minister, Des Browne, pulled out of a debate; and a Conservative MP, Julian Lewis, went one step further, tearing up his life membership of the prestigious union which he said was giving a "boost" to "a couple of scoundrels who can put up with anything except being ignored."
"It's not an issue of free speech to offer someone a privileged platform from a prestige organization," he told the BBC.
The Oxford Union has cited a form of "Voltaire defense" to back its case. The great French philosopher once made an implacable defense of free speech, saying "I disapprove of what you say, but I will defend to the death your right to say it." Such notions are upheld in British law, which, although intolerant of hate crimes, slander, libel, and indecency, is relatively permissive of what people can say in public.
Luke Tryl, the union president, says though he disapproves of the views of Irving and Griffin, the best way to defeat and discredit them is in open debate. Conversely, muzzling them would risk turning bigots into free speech martyrs.
"The reason the Oxford Union was founded 184 years ago was to promote and defend freedom of speech," Mr. Tryl said. "This is what this debate is about."
Opponents have countered that free speech has its limits, as perhaps best summed up by the old adage that you shouldn't shout "fire" in a crowded theater. (It originates from a judgment by the former US Supreme Court justice Oliver Wendell Holmes, who wrote in 1919: "The most stringent protection of free speech would not protect a man falsely shouting 'fire' in a theatre.")
The argument turns principally on the opinions of the two men. Irving is a historian who has specialized in the military history of World War II. But his work has been widely discredited for being ideologically skewed. Last year, he served 13 months in an Austrian prison for Holocaust denial, an offense in several European countries.
Griffin also has a criminal record, having been prosecuted for inciting racial hatred. He has also publicly denied and belittled the Holocaust.
The undergraduate community at Oxford is deeply conflicted by the event. On Friday, students voted in favor of the debate going ahead, with around 1,000 supporting Tryl and 600 against. One undergraduate said the atmosphere was tense on Monday, with buses of antifascists and BNP supporters arriving to air their views. Some have warned that student safety may be jeopardized.
"At the beginning I was pretty open-minded because free speech is a good thing," says the undergraduate, who did not wish to be named. "But now it seems we are giving these men more prestige than they deserve. There is quite a lot of concern that tonight's debate won't be balanced."
The entire event bears striking similarities to the row that erupted in September when Columbia University, in New York, invited Iran's President Mahmoud Ahmadinejad to give a talk, prompting accusations that it was allowing an anti-Semitic Holocaust-denier to extol his views on a Western stage.
On that occasion, the University's president, Lee Bollinger, argued that listening to objectionable ideas was very different from endorsing them, and added that it was important not to "honor the dishonorable when we open the public forum to their voices."
With this in mind, he publicly excoriated Mr. Ahmadinejad as he introduced him. It remained to be seen Monday what kind of reception Irving and Griffin would get.