On August 15 1939, British spy Mr Wheatley (Nigel Lindsay) realises his cover as an English teacher at Augusta-Victoria College in Bexhill-on-Sea has been blown.

He hastily arranges a rendezvous with his superior, Colonel Smith (David Schofield), but an enemy operative intervenes.

A few days later, headmistress Miss Rocholl (Dame Judi Dench) interviews journeyman teacher Thomas Miller (Eddie Izzard) as a replacement to prepare German girls for their introduction to polite British society.

Six Minutes To Midnight is a slow-burning espionage thriller based on a real-life finishing school on the south coast of England, which polished German girls between 1932 and 1939.

Director Andy Goddard’s fitfully entertaining if occasionally far-fetched yarn engineers dramatic tension with an arbitrary 24-hour countdown to Prime Minister Neville Chamberlain’s declaration of war on Germany.

Izzard isn’t wholly convincing as a skilled pawn of the British government and his haphazard course through the film relies more on luck than skill. Dench lends gravitas to her misguided educator, while there is a colourful if entirely superfluous supporting performance from Jim Broadbent as a rosy-cheeked bus driver invigorates a chase sequence in the briskly paced second half.