Operation Mincemeat stars Colin Firth in a straightforward retelling of a WWII strategy to trick Nazis with a decoy corpse

Director John Madden told Empire the movie doesn't always take itself seriously because the idea at its centre "edges over into Monty Python territory". (Supplied: Transmission)

It might sound like the title for a gory, straight-to-video action movie, but Operation Mincemeat was a real World War II strategy – a secret Allied scheme to deceive the Nazis by dropping a corpse carrying fake military plans into enemy terrain, in the hopes that it might divert Hitler's forces from the real invasion planned for Sicily.

Despite the absurdist potential of a story involving a reluctantly heroic stiff, this version of the event, from British filmmaker John Madden (The Best Exotic Marigold Hotel; Shakespeare in Love), is an earnest and tastefully mounted dramatic thriller starring a cast of plummy thespians, including not one but two erstwhile Mr Darcys, in Colin Firth and Matthew Macfadyen (Pride and Prejudice).