OXFORD University’s debating society has withdrawn an invitation to a euthanasia activist who was set to speak at the union.

The Oxford Union had invited Dr Philip Nitschke, the first doctor in the world to administer a voluntary lethal injection, to speak at a debate in May.

But Dr Nitschke, director of Australia’s leading right to die advocacy organization, Exit International, claimed the invitation was withdrawn just two days later by union president, Corey Dixon.

Dr Nitschke said in a statement: “This famous society has a long tradition of championing free speech.

“To suggest that my views on end-of-life issues are inappropriate simply because I believe that all rational elderly adults should have access to the best end-of-life information beggars belief.”

Union president Mr Dixon told the Australian Associated Press: “We wanted to hear him speak. However all the other people who we also wanted to invite to speak in favour of assisted suicide were unwilling to speak alongside him — the reason being they disagree with his particular take on it.

“I hope it doesn't appear badly on ourselves, but obviously the most important thing for the Oxford Union is to have a balance and as wide-ranged views as possible, and if these people were unwilling to speak alongside him, then it would give a very narrow proposition line.”

Mr Dixon said Lesley Close, whose brother John went to Switzerland for an assisted death in 2002, was one of the people who did not wish to speak alongside Dr Nitschke. British euthanasia campaigner Dr Michael Irwin was another.