Sir Michael Caine has voiced his support for David Cameron's idea of citizens' national service for teenagers Link to this video

Not a lot of people knew that Michael Caine was set to be the Conservative party's secret weapon in the general election campaign.

But today, the Oscar-winning actor, who last year threatened to leave the country for tax reasons, stood alongside David Cameron and backed his plans to set up a "non-military" national service scheme.

More on this: