08/11/2012 08:20 GMT | Updated 07/01/2013 10:12 GMT

Cameron Diaz Reveals Her Friends' Envy For Her Co-Starring Role With Colin Firth In 'Gambit'

Cameron Diaz has revealed she provoked great envy from her female friends when she signed up to star alongside Colin Firth in new film 'Gambit'.

The pair play accomplices who try and con England's richest man into buying a fake Monet painting in the crime caper, a remake of the 1966 comedy starring Sir Michael Caine and Shirley MacLaine.

At the film's world premiere in London's Leicester Square, Cameron said working with the Oscar-winning 'The King's Speech' star was "a pure joy".

colin firth cameron diaz

Colin Firth and Cameron Diaz in criminally good form on the red carpet in London

The actress, who walked the red carpet in a monochrome Stella McCartney dress and jacket, added: "All of my girlfriends, as soon as I said that I was doing a film with Colin Firth, they were like, 'You mean with my boyfriend?'"

Firth's art expert character spends a significant portion of the film with no trousers on, after a mishap on a window ledge at the luxurious Savoy Hotel.

"It's knee porn," the actor quipped.

"I did lose a pair of trousers, which is standard farce material. I spent quite a long time filming in that condition but you'll be pleased to hear I can't promise you any more than my knees."

Colin Firth, Cameron Diaz And Co

Diaz and Firth were joined at London's Empire cinema by director Michael Hoffman and co-stars Alan Rickman and Sir Tom Courtenay.

Rickman, who plays billionaire Lionel Shabandar in the film, was required to go even further than Firth and strip off completely for the film. But he insisted baring all did not bother him.

"It's just the opposite of putting clothes on. Sometimes you get costumes you can't bear wearing, so sometimes it turns out it's a relief not to say, 'I don't like this costume'," he added.

Gambit is in UK cinemas on 21 November. Watch the trailer below...