An unemployed printer and an amateur rapper are among a group of non-actors who agreed to appear in a feature film for a bit of a laugh. They never expected it to be selected for one of the most prestigious events in the industry’s calendar, the Venice Film Festival.

Exodus features 25 nonactors who were given speaking roles, and more than 800 extras. All are from Margate, Kent, which thrived when Turner painted there but which today is defined by unemployment, drugs, crime and asylum-seekers.

Some answered an advertisement in their local newspaper. Others were cast from schools, shops, pubs, clubs and community centres, or simply off the street because they had the right look.

Michelle Lam, an 18-year-old school leaver, said: “It doesn’t seem real.” She had been urged to go along to the audition by a friend who had seen an advertisement. She found herself being cast as a “computer geek”, while her friend was asked to come back as an extra.

Delroy Moore, a 50-year-old unemployed printer who is a foster carer, was asked to play a schoolteacher, even though he had “never, ever acted before – not even at school”. He said: “It was very scary at first, I must confess. The first time I saw the film I was very nervous, but it’s truly amazing.”

He got involved with the production through a friend, helping out behind the scenes. Then he was urged to audition and was cast after he gave a convincing performance as an angry resident.

Exodus tells the story of a politician, Pharoah Mann, who has found the perfect solution for the Promised Land. All the problem elements of society – asylum-seekers and economic refugees, the long-term unemployed, sexual deviants, substance abusers, petty criminals and ethnic minorities – are forced to live in Dreamland, a shanty town built on the site of a disused funfair. It was written and directed by Penny Woolcock, an acclaimed film-maker whose work has repeatedly portrayed life on Britain’s toughest housing estates. She directed The Principles of Lust, which won an award at Sundance in 2004.

She said: “Margate is a little seaside town on the south coast of England where working-class people used to go for their holidays. These days the town has become very poor and its beautiful beaches and dilapidated hotels are mostly empty.

“Asylum-seekers, who occupy a big sea-front hotel and have fled war-torn areas across the world, from the Congo to Iraq, are bitterly resented by some local residents who feel marginalised and neglected. Margate became the setting for Exodus.

“The emotional truths of the Old Testament, where the oppressed are brutalised and become brutal, where terrible injustice leads to horrific acts of terrorism, are all as vital today as they were in Biblical times.”

She cast Daniel Percival, a young actor just out of drama school, as Moses, alongside Anthony Johnson, a local rapper, as his brother Aaron.

She said: “Asylum-seekers worked alongside impoverished people who might have resented them, people with special needs and those who might have taunted them. But friendships were formed and a peaceful atmosphere prevailed for the shoot.

“For me the whole process was profoundly linked to the heart of the film, and it is what gives it life.”

Fresh from the Bond film Casino Royale, the production designer Christina Moore worked with both experienced set builders and local graffiti artists. The professional cast was headed by Bernard Hill. The production, funded by Channel 4 and Arts Council England, among others, is a first feature film from the Artangel organisation, which is devoted to making art outside the confines of gallery walls.

Explore Film

• Film Reviews

• DVD

• Oscars

• Bollywood

Editor's choice

• The top 10 fan versus band scuffles
• Mamma Mia! The first review
• Times critics' 20 best films for kids