Close-up: Liam Cunningham

Can the actor's role as a priest help Ireland come to terms with its past?

When Liam Cunningham was invited to audition for Hunger, Steve McQueen's film about the 1981 IRA hunger strike in Northern Ireland's Maze prison, his reaction was hardly one of delight. "As soon as Bobby Sands' name was mooted, I grimaced; it's still an open wound in Ireland," says the 47-year-old Dubliner.

The 27-year-old Sands starved himself to death in 1981 in an attempt to win political-prisoner status, and remains an emotive symbol of the complexity of Ireland's past. "I remember all these black flags in windows in Dublin at the time," Cunningham recalls. "And there was Margaret Thatcher on TV trying to dehumanise these men."

It was the combination of McQueen's thoughtful approach and Enda Walsh's powerful script that led Cunningham to accept the role of the prison priest with whom Sands (played by Michael Fassbender) debates the morality of his protest. Their impassioned exchange – shot in an incredible, 22-minute single take – is the centrepiece of a largely dialogue-free film. "When Steven told us how he wanted to shoot it, Michael and I looked at each other and said, 'We'll have to move in together.' We spent five days going through that scene 15 times a day. The assistant producer would come round to slide our lunch under the door."

Having played an IRA member in Ken Loach's The Wind that Shakes the Barley (2006), does Cunningham see Ireland coming to terms with its past through such films? "It's a measure of the peace process that we are able to deal with this on screen," he reflects. "Some beautiful art has come out of a horrific situation."

'Hunger' (15) is screened today and tomorrow at the London Film Festival ( www.bfi.org.uk/lff/). It is released in cinemas on 31 October