Sir Stewart Menzies, pictured in 1915, went on to lead MI6 during the Second World War

He was the wartime spy chief who oversaw Britain’s success in breaking the Nazis’ Enigma code. Without him, Bletchley Park would not have been the massive operation that it became.

Yet according to English Heritage, Sir Stewart Menzies is not as historically important as Britain’s first woman dentist, or the man who gave his name to the J Lyons restaurant chain.

The charity has turned down an application to honour Menzies with a blue plaque at the house in central London that was his home when he ran MI6 during the Second World War.

Menzies supervised the vital code-breaking activity at Bletchley Park JACK TAYLOR/GETTY IMAGES

English Heritage said in its rejection letter: “His overall historical profile was not quite strong enough for his name to be added to the shortlist.”

This year English Heritage announced plaques