The Prime Minister, speaking at a secret war cabinet meeting in July 1942, described the German leader as "the mainspring of evil" and suggested leasing an electric chair from the Americans to execute him like "a gangster" if and when he was caught.

At one meeting, on 6 July 1942, Churchill said: "If Hitler falls into our hands we shall certainly put him to death. [He is] not a sovereign who could be said to be in [the] hands of Ministers, like [the] Kaiser."

The Prime Minister then went on to outline his preferred method for Hitler's execution: the most tortuous and evocative means available . . .

the electric chair. He even joked to Cabinet colleagues that one might be available on "lease lend" from the US.

Cabinet Office historian Gill Bennett said the idea of using the electric chair to execute Hitler was "typical Churchill".

"This is very much Churchill's style. He was always a man of grand gestures, and he said what he felt the British people would want, " said Bennett. "Amongst the Brits, who had been fighting a lot longer than the Americans or Russians, there was a sense that these were very bad people who should be disposed of.

The whole Cabinet felt very strongly about the evilness of the Nazi leaders."

At another meeting of the war cabinet in May 1945, Churchill addressed the fate of Hitler's right-hand man, Heinrich Himmler, and is recorded asking whether it would be possible to "negotiate" with the former head of the Gestapo, "and bump him off later." Ultimately, Himmler, like Hitler, committed suicide before he could be brought to trial.