John Cleese has "blacklisted" himself from the Cambridge Union for his own impression of Adolf Hitler. The 82-year-old comedian has pulled out of an appearance later this week after art historian Andrew Graham-Dixon was banned from speaking at Cambridge University after he offended students by mimicking the leader of the Nazi party. Taking to Twitter, Cleese said: "I was looking forward to talking to students at the Cambridge Union this Friday, but I hear that someone there has been blacklisted for doing an impersonation of Hitler. "I regret that I did the same on a Monty Python show, so I...