Public figures have leaped to the defence of a TV historian who was placed on a “blacklist” of speakers at the Cambridge Union after he jokingly impersonated Hitler.

In the debate on the subject of “good taste” last week, Andrew Graham-Dixon paraphrased Hitler’s racist rants — using a German accent — to illustrate a link between bad taste and immorality.

In a statement to the JC, fellow historian Guy Walters said: “The idea that Andrew Graham-Dixon has been blacklisted for performing what was clearly a satirical impression of Adolf Hitler is both disgraceful and deeply ironic.

“Banning and blacklisting are, after all, some of the favourite tactics of those who seek to repress freedom of expression. It’s not impossible we will soon see our first book burning on a British or US university campus.”

His outspoken defence joined those of novelist Louis de Bernières and Fawlty Towers star John Cleese, who “blacklisted himself” in sympathy.

But Mr Graham-Dixon’s impression was criticised by Cambridge JSoc, which said in a statement: “Whilst we understand it was a light-hearted debate, the impression of Hitler and language used was insensitive and made a number of people feel uncomfortable and represents a serious misjudgment on the part of the speaker.”

Mr Andrew-Dixon responded: “In my speech I caricatured Hitler, briefly, paraphrasing his crass and insensitive statements about art and race. I apologise sincerely to anyone who found my debating tactics and use of Hitler’s language distressing; on reflection I can see some of the words I used, even in quotation, are inherently offensive.”

After the event, the president of the Cambridge Union, Keir Bradwell, accused Mr Graham-Dixon of “grotesque language”. He also told the Telegraph that he would “create a blacklist of speakers never to be invited back” and confirmed that Mr Graham-Dixon would be included on it.

Mr Bradwell said in a statement to the JC that he had drunk two glasses of wine before the event and was heard saying “I’m quite drunk” while presiding over the debate. But he denied that it had affected his judgment.

In a statement to Cambridge Union members, Mr Bradwell said: “Neither I nor the society condones the thoughtless and grotesque language used by the individual in question, and I am sorry for my failure to intervene.” He has now said the planned blacklist will not go ahead.