Jagger and Winslet an enigma: There was something less than excitement at Bletchley Park, home to the Second World War codebreakers, when Mick Jagger walked in last Wednesday, unannounced, with a pregnant Kate Winslet on his arm.

The pair were on a recce for the film adaptation of Robert Harris's bestselling book Enigma, about the Bletchley Park team who broke the German ciphers.

Winslet plays the love interest in the film - due to start shooting on April 17 at nearby Chichley, another country house. Jagger's interest is that his own embryonic film company is making Enigma with a script by Tom Stoppard.

He is also a keen collector of military memorabilia and was carrying an original German three rotor Enigma machine.

He explained to the Bletchley Park museum staff that it was his, it was broken and he asked them if they would be kind enough to repair it.

"I was in a board meeting all day," says Christine Large, the director, battling to improve the museum. "I wouldn't have noticed if the Archbishop of Canterbury had turned up."