Labour has recruited two big-name actors to front its first party election broadcast as the battle for celebrity endorsements hots up in the weeks before May 7.

The short film, due to be aired tomorrow, features Sherlock and The Hobbit star Martin Freeman giving his backing to the party and warning the Conservatives have "sod-all to offer the young".

"Really, for me, there's only one choice, and I choose Labour," he declares.

The voiceover is supplied by former Doctor Who and Broadchurch star David Tennant.