Students at Oxford University are poised to set up a campaign in opposition to Nick Griffin and David Irving speaking at the Oxford Union’s Freedom of Speech forum.

Although the line-up for the forum has yet to be confirmed, the union has invited British National Party leader Nick Griffin and controversial historian David Irving to discuss the limitations of free speech. Campaign groups Unite Against Fascism and the National Union of Students have both condemned the decision.

Gemma Tumelty, President of the National Union of Students (NUS) said: "The pair's racist, anti-Semitic, homophobic and Islamophobic views threaten the safety of our diverse university communities. Wherever the BNP is active, racist attacks and other hate crimes increase."

Pledging to support moves to have the invitation reversed she added: "It is unacceptable to expose students and staff to the possibility of attacks and to give a platform of academic respectability to Griffin and Irving."

Former Cambridge student Mr Griffin was shown in an undercover BBC documentary describing Islam as a "wicked and vicious faith" in 2004. He was later found not guilty on two occasions of using words or behaviours intended to stir up racial hatred, and condemned the government for announcing a review of the law in the aftermath of the case.

Mr Irving was jailed for ten months in Austria in 2006 for glorifying and associating with the Nazi Party, and faces further charges for Holocaust denial in the country. He has been accused of manipulating historical evidence and criticised by Jewish groups for denying the extent of Nazi genocide during the Second World War.

Unite Against Fascism spokesperson Weyman Bennet warned against giving Irving and Griffin a platform, he said: "Millions were murdered in the holocaust not because their arguments weren't good enough, but because those who could have stopped fascism under-estimated the threat it represented. Many thought its flaws so obvious they could easily be exposed."

However, the Oxford Union has denied giving a level of legitimacy to the arguments of both Mr Irving and Mr Griffin.

In a letter to students, President Luke Tryl said: "These people are not being given an opportunity to extoll their views, but are coming to talk about the limits of free speech.

"Stopping these people from speaking only allows them to become free speech martyrs, and from my experience groups like the BNP do well if they look like they’re being censored.

"I think it's patronising to suggest that Oxford students aren't intelligent enough to debate these people, and I have great faith in the ability of Oxford students to challenge them.

"I realise that this is a difficult area but the Union was founded particularly to discuss and promote free speech."