In an unfortunate incident similar to a Father Ted episode where a perfectly square piece of dirt gave the Irish priest a moustache, the Ukip leader was left talking about an immigration crackdown with a large black pixel over his upper lip.

He had been talking to the broadcaster about Enoch Powell following revelations that teachers saw him as a ‘racist’ and a ‘fascist’ at school.

The Ukip leader was forced to deny that he sang Hitler youth songs at school, after a teacher alleged that, at a Combined Cadet Force camp organised by Dulwich college, Mr Farage and others had marched through a Sussex village “shouting Hitler-youth songs”.

The picture was originally tweeted by BBC TV Sportscaster Olly Foster, before he deleted the post saying: “Apologies for my previous tweet. An error of judgement on my behalf.”

The BBC said in a statement “The big screen is owned by MediaCity UK, not the BBC. The fault has been reported to them and they are working to rectify it as soon as possible.”