British actor Colin Firth tells his two young sons he works with cranes and machinery - because it sounds more manly than acting.

The BRIDGET JONES' DIARY star, who has two children, LUCA, four, and Mateo, two, with his wife LIVIA, is keen for his offspring to believe his career involves more masculine work than dressing up in front of a camera.

He says, "(Luca) came to see me while I was making the film NANNY MCPHEE, but he didn't really have any concept of what we were doing there.

"He seemed most interested in the cameras and cables, so we have developed the idea with him that I work with cranes and heavy machinery.

"He did seem to like that thought, and I didn't want to crush his idea that I do something manly with my life, instead of what I really do - putting on costumes and make-up, and flouncing around in front of the camera."