内容摘要：The 22-year-old, from Bishops Waltham, Hampshire, began his challenge on 26 January and completed it on 6 February.

The 22-year-old, from Bishops Waltham, Hampshire, began his challenge on 26 January and completed it on 6 February.

At the gala screening at the Ham Yard Hotel, London, Griffiths said, "Tom especially was going blue through most of the takes."I think there was a medic going in, and you too, right [Mulligan]? We had a medic sort of checking your temperature for the cold stuff. It was freezing."

Mulligan added it was special as she just had a baby when they started filming."It's just attached to all these gorgeous memories of my baby being little."And you guys were all around, and everyone was cuddling her, and we were all sort of together for a bit. So it's very precious to me."

Key said: "We shot the short film (version) 18 years ago, and we're kind of very eager to get back to Wales. Feels like it's a big part of the film. Weirdly."Basden said the filming location was "beautiful" but "unpredictable weather wise".

The original short film, The One And Only Herb McGwyer Plays Wallis Island, was nominated for a 2008 Bafta short film prize, and saw Key and Basden in the main roles.

The Wychwood Festival is returning to Cheltenham Racecourse this weekend as the summer of live music gets under way across the West.When asked if it was filmed in the summer, Oscar-nominated actor Mulligan, whose mother is from Llandeilo in Carmarthenshire, said: "It's Wales."

In the film, Mulligan plays on half of a disbanded folk band with her ex-boyfriend, played by Plebs star Basden.They are paid to reunite for a gig on an island called Wallis by a fan and lottery winner, played by comedian Key.

Mulligan, 40, said filming over a few weeks felt like a "summer camp together".At the gala screening at the Ham Yard Hotel, London, Griffiths said, "Tom especially was going blue through most of the takes.