Artist Louis Sidoli morphed an image of the Führer — under the heading “Reign of Terror” — into the present encumbent of Downing Street with the title “Reign of Error”.

Described on his website as “the UK’s foremost contemporary Glass Artist”, the Anglo-Italian adds: “The similarities between the two personalities are striking: both started out as Chancellors, both bullied their way to the top and seized power without democratic election, both [are] notorious for flying into uncontrollable rages and both caused enormous damage to the country.”

The artworks — which he says were inspired by the art that blossomed during the campaign of Barack Obama in the US — come amid allegations in political commentator Andrew Rawnsley’s book The End of the Party that Downing Street is dominated by the Prime Minister’s alleged violent tantrums and outbursts of anger.

But Sidoli’s endeavours have found little favour with Lord Janner, a barrister, Labour Member of the House of Lords and former President of the Board of Deputies of British Jews.

He told Mandrake the comparison was “offensive rubbish”: “I have known Gordon Brown for well over 20 years as a parliamentary colleague and as a friend and can categorically guarantee that these allegations are totally unfounded.

"I think we have some laws on defamation that could and should be used where those defamed want to.”