On a cloudy Monday afternoon, Bill Nighy is standing in the middle of a football pitch in south London.

"Come on you lot, let’s go," the actor shouts at a couple of dozen men who have turned up hoping to be selected to represent their country.

Nighy is channelling his most recent character - a football coach who takes an England squad to an international tournament.

The tournament is the Homeless World Cup, and to promote his new film The Beautiful Game, the Oscar-nominated actor has turned up to the real-life trials for the next event in South Korea.

"I didn’t know anything about the Homeless World Cup before, but it really is a simple and sensational idea," Nighy says.

For him, one of the best things about being part of the film was meeting the extras who had participated in real tournaments and are now no longer homeless. "It’s a very sweet bit of symmetry," Nighy tells the BBC.

The Homeless World Cup involves a four-a-side format, and the film strips football back to its basics - removing the fame, money and power that are sometimes associated with the game.

Although The Beautiful Game shows the potential for sport to create change, the actor - a Crystal Palace fan - confesses he’s not sure whether football actually has that power.

"I’m not sure really," he says. "But I think it does bring everyone closer and brings people from all of the world together. It’s a universal language for about half of the world, and I think to some degree it can alleviate prejudice."

England’s real coach for the Homeless World Cup is Frankie Juma, who started playing football in the UK when he joined a refugee team.

Frankie Juma started playing for a refugee team when he came to the UK from Sudan

He says he wanted to become a coach in order to give back to the community. "It’s nice to do something that gives back to the country that gave me a safe space, and I like helping people and making those that had similar experiences to me feel comfortable."

At Juma’s training sessions, it’s not just about football.

"We probably do 30% football and 70% support because the people that come to us often need access to education or services such as housing, which is a huge issue right now," he explains.

Juma is now on the hunt for eight men who will represent England at the forthcoming Homeless World Cup in September.

The Sudanese refugee taking England’s homeless football to the world cup

One player that has caught his eye is 35-year-old Courtney, who has had his share of ups and downs.

"I’m getting back into football now because it really helps me de-stress and it makes me forget about everything in life, because I just want to have fun and build up my fitness," he says.

Football has helped him avoid homelessness, he says. "If I’m out here, I’m not doing things I shouldn’t be."

Courtney says football helps him take his mind off other things

Courtney says it would be a dream to represent England.

"Some people would say I’m the black Tony Adams, and if we stay focused there is no reason why we can’t go all the way."

One member of the film’s cast who particularly related to Courtney’s experience of homelessness is Micheal Ward.

Ward plays Vinny, a star player who is living in his car after his relationship broke down, and the Top Boy actor himself experienced homelessness growing up.

"Me and my family have been homeless many times and I hadn’t realised it because my mum would try to cover it up, and the times she wasn’t able to do that she would make a joke about it. So I never understood the seriousness behind it," he tells the BBC.

Micheal Ward experienced homelessness growing up

Ward found a new perspective on homelessness after spending time with the film’s extras, who were former participants in the Homeless World Cup.

"I want people to take away the idea that you shouldn’t judge a book by its cover. I’m guilty of doing that and seeing people on the street thinking, what the hell? But you realise that a lot of the situations they are in are not their fault, or they are spiralling and we don’t know the source of that.

"I now try to be more aware and do a little bit more to help."