This Country star on reuniting duo for whodunnit See How They Run

And the director was also able to call on help from some of his old collaborators, with This Country star and co-writer Charlie Cooper taking on the role of a nervous theatre usher.

"Tom just rang me saying, 'Look, I've been asked to do this massive film. I'm f**king terrified. Will you be a part in it so I've got a mate on set that I can talk to?'" Cooper explains to RadioTimes.com during an exclusive interview.

"So I was like, 'Yeah absolutely!' And then he told me who's in it, and I was like, 'Are you sure you want me to be in this!?' But no, I mean I haven't really done a film like this before, so it would have been a bit terrifying had I not known the director like Tom. We had that relationship, and that was really nice, put me at ease."

Terrified or not, the film worked out very well – and George says that in the end, the process wasn't as different from This Country as you might imagine, even if things were on a much bigger scale.

"There was obviously an extra layer to the production, mainly because this was a period piece," he says. "And so that brings with it more production design elements, costume elements, [and] some visual effects to create period London.

"But at the same time, it was reassuring that it was similar. And for me, the most important thing is always [the] performance and making sure that no matter how big the production has got, when you're filming you just want to feel like it's a handful of you trying to make the best thing that you can on the day.

"So you kind of forget about those other elements and try and keep the atmosphere similar, so that actually it ended up a very similar working approach to my work on This Country."

For Cooper's part, there were a couple of main differences between acting in a relatively small-scale sitcom and a big feature film such as this.

"It's just such a bigger beast," he reveals. "So many more people are involved, so many more people around the monitors and watching you on set. I mean, with This Country, we filmed it all on a pretty low budget on location in Gloucestershire!"

But also, the film gave him the chance to work with the aforementioned ensemble cast – something which left him a little starstruck, especially when it came to his scenes with Adrien Brody.

"I mean, The Pianist for me is like one of the best films ever," he explains. "And because he's got such an iconic look, it's just a face you'll never ever forget, and he's such an amazing actor. So we had some rehearsals with him – and just him looking into your eyes was incredible. Seeing him doing stuff in person was like a privilege – it felt like I'd won a competition or something!"

It remains to be seen what's next for George, but Cooper reckons the sky is the limit for his collaborator.

"I think – because he's so talented – Tom could just end up going up and up and up and up," he says. "I think there's just no ceiling for him. So being able to be involved in seeing that journey from the very, very beginning is so amazing. But he hasn't got an ego, he hasn't changed the way he talks to people, and he's still humble, Which is really nice.

"Although he could become a d**khead later on!" he jokes.

See How They Run is released in UK cinemas on Friday 9th September. Check out more of our Film coverage or visit our TV Guide to see what's on tonight.

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