Hundreds of people have staged a protest against Oxford University's debating society for inviting Holocaust denier, David Irving.

The 184-year-old debating society of the Oxford Union invited Irving to speak along with Nick Griffin, the leader of the extreme far-right British National Party.

Politicians have slammed the union and said the student organisation is giving a platform to extremism partly in an effort to attract attention.

Julian Lewis, a Conservative member of Parliament, has resigned his membership of the union. Also British Defence Secretary Des Browne, television anchor June Sarpong, Labour Parliament member Austin Mitchell and other prominent Britons have called off engagements to speak in future debates.

However, Oxford Union President Luke Tryl has defended the invitation, saying the best way to counter extremism is to defeat it intellectually in debate. Irving is a historian and writer of 30 books denying the Holocaust. In 2006 he served a prison sentence in Austria for denying the Holocaust.