Copping off

It happened when he and Page, star of award-winning comedy Gavin & Stacey, appeared in a film together recently. He was playing her boyfriend, whom she had to kick out of bed.

"I was supposed to be naked," explains Thornton. "I had to wear a little fleshcoloured thong and was marching around before a take, trying to be serious and getting into character.

"We were supposed to be having a row in the scene but Jo couldn't stop laughing at me.

We just found the whole thing hilarious."

The pair previously worked together on a screen adaptation of David Copperfield, but Thornton's not sure a guest appearance on Gavin & Stacey would be advisable.

"I don't think that would be a good idea. It's really funny seeing your partner acting because you know each other too well to believe them," he says.

In Holby Blue, he's PC Jake Loughton, who resents being transferred from the North and manages to offend his first partner at the precinct in the process.

He's played a nurse in No Angels and now he's a police officer. He's already completed his public service hat-trick by portraying a fireman in Playing The Field, in which he played women's football team coach Scott Bradley. "I've never thought of it before, but I do have the full set now," says Thornton.

"My wife loves it.

She said she fell in love with me w h e n s h e s a w me in my fireman's trousers and white vest. We weren't together at the time but it did the trick. I suppose I should have kept all my costumes just in case the acting doesn't work out. I could start a strip act."

He was in the military police, as Sergeant Philip "Hippie" Roper, in a previous BBC1 series, Red Cap. He says the police force is just as exciting as the Army, although the two characters are very different.

Roper was the military equivalent of CID, wore a suit and led many of the cases. PC Jake Loughton is much more hands-on. "I spend most of my time in uniform and get to investigate the crimes as they happen on the street," says the actor.

"I really loved working on Red Cap because, like Holby Blue, the cast were great fun and I got to run around with a gun and drive around in jeeps and tanks."

He's done films but Hollywood doesn't appeal, partly because he wouldn't be able to take his beloved Jack Russell terrier, Daisy, with him.

"I'd love to do an American show like Heroes since I'm a massive fan. I don't think I could leave the UK permanently, though. I would miss jogging round the park with Daisy going for my ankles," he says.

He sang on some of the tracks on the film, Among Giants. There are no plans to take his singing career further. "My wife bought me the Sing Star game for my PlayStation for Christmas and I do a very original version of Ice, Ice Baby by Vanilla Ice. I think I'll keep that to the privacy of my own living room, though."

As for PC Loughton, his transfer to Holby Blue is not as straightforward as it seems.

He's moved from Preston, causing fellow Northerner PC Lucy Slater to question him about it.

HE'S very guarded about his reasons for moving and not particularly forthcoming with any details regarding his personal life," says Thornton.

"It's clear he's pretty experienced in his job right from the start as he seems very assertive and self-assured. This only serves to intrigue Lucy even more."

Thornton finds it great fun dressing up as a cop and pretending to catch criminals, but he's learnt to be careful when filming in uniform on location.

"We were filming out near some woods and I was desperate for a wee," he says. "We had no toilets and were pushed for time to get everything shot before it got dark. I was bursting and nipped behind a tree. Afterwards, I realised it must have looked really weird to anyone who didn't know I was a fake policeman.

"So to anyone out in Chertsey who may have been worried that the local police are inconsiderate louts, they're really lovely and would never wee in the woods. It was me and I'm very, very sorry."

* Holby Blue: Thursday, BBC1, 8pm.