The award-winning script orbited the writer's head for years. Now that Headrush is finally ready for release, Shimmy Marcus hopes his Irish comedy-caper-thriller won't be dismissed as yet another Lock, Stock wannabe, he tells Michael Dwyer

IT'S been a long haul. The exuberant caper comedy Headrush opens at 10 Irish cinemas today, having finished shooting back in January 2003. Its gestation dates back to Christmas 1994, when director Shimmy Marcus wrote the first draft of the screenplay. It's been tough, but a labour of love, says Marcus, who was known as Simon until his childhood nickname stuck.

"When I started writing Headrush, it was before Trainspotting and Lock Stock and all those other films came out," he says. "That whole genre got completely dated. It was so frustrating to see these things coming out, one by one, and there was the fear that we were going to miss the boat, or that we would be seen as trying to follow in their footsteps. In a positive sense, all that forced me to do something different and quirkier with the genre so that it didn't conform to the norms of a gangster comedy."

The reference points he cites for his movie are not the British guns'n'geezers cycle of the 1990s, but "goofy stuff" such as Withnail & I, Cheech and Chong films and The Lavender Hill Mob.

"It wasn't until after I'd written it that I realised where some of the inspiration was coming from. You tend to soak a lot of this stuff up while you're watching other movies, and it's only later that you realise it. I was lucky when I was growing up, because I had a nice mix of Hollywood films along with Jacques Tati films and old Ealing comedies most kids my age wouldn't have seen then."

Marcus grew up in a film-making background, to which he says he was oblivious in his younger days. His father, Louis Marcus - who has a cameo in Headrush as a violin-playing busker - was one of the pioneers of indigenous Irish cinema, persevering to get movies made at a time when there was no such thing as an Irish film industry. In 1974 Marcus snr received an Oscar nomination for his short film, Páistí ag Obair (Children at Work), and two years later was nominated again for Conquest of Light.

What advice did Shimmy receive from his father? "I never got the Polonius speech," he says. "But then, I never announced that I was going to become a film-maker. I just segued into it sideways and would get little bits of advice along the way. Growing up, I just took it for granted that my father was a film-maker.

"When he would come from the Oscars, my first reaction was to ask where were my presents. It wasn't until I got much older that I really appreciated what he was doing out there in the shed in the garden, editing on his Steenbeck. He was the original auteur. He did everything - he wrote the scripts, produced and directed the films, and edited them."

Prior to making Headrush, Shimmy Marcus directed an imaginatively structured and warmly received documentary, Aidan Walsh - Master of the Universe.

"That got a fantastic reaction, but I got an uneasy sense that people felt that here's a documentary film-maker trying to become a drama film-maker. In fact, I never set out to make a documentary. My attitude was that here was an extraordinary story and I wanted to tell it in the most creative and entertaining way possible.

"I realised then that there are serious responsibilities when you're dealing with somebody's life. I wanted to get people laughing at the start and then to turn the tone more serious as we reveal more about him. I was just exceptionally lucky to know Aidan and to have that opportunity to tell his story."

While Marcus was working on that film in 1999, he won the Miramax Scriptwriting Award for Headrush. "That was huge," he says. "First of all, it gave the project credibility. People began to take notice and to take it seriously. When you have Miramax attached to anything, it's amazing how many doors it will open to people who might not read it otherwise. And certainly in the marketing of a film, when you don't have any Hollywood stars in it, you need those awards to put them on the poster."

The arduous journey that was the making of Headrush was marked by unfortunate events. Sheer stress led to Marcus being hospitalised with kidney stones. In Cannes to raise finance for the film, he lost his own money to a pickpocket. When the film was shooting, one actor, Gavin Kelty, was sent to hospital with a suspected broken arm after a struggle with Steven Berkoff; another, Tom Hickey, was struck by a bicycle.

The temperature was -7 when the Amsterdam scenes were shot in January 2002. And when Marcus presented Headrush at the East Lansing Film Festival in Michigan, where it won a prize, he was teargassed by police attempting to pre-empt a student riot that never happened. "They were incredibly intimidating and the gas was blinding," he recalls.

Worst of all, Gary Lewis, who was to play the villainous character, The Uncle, had to withdraw from the film the week before it started shooting. "It wasn't just the timing, but the fact that he's such a phenomenal performer," says Marcus. "He got delayed on a movie he was shooting in Hungary that went over schedule. I was gutted when he couldn't make it."

Was it easy to get Steven Berkoff off the peg, so to speak, to replace Lewis? "I made a couple of phone calls and he agreed. Berkoff really enjoys working with first-time directors, not because he can intimidate them but because he gets a chance to improvise that he wouldn't get on a Hollywood set. Our schedule was flexible enough and I enjoyed being able to give him that freedom. He came up with a few interesting things that came from his own dark personality. He put the fear of God into everyone on the set."

Headrush has screened at film festivals all over the world, collecting a number of awards along the way. ("Young audiences love it.") However, in getting the film released in Ireland, he and producer Edwina Forkin are distributing it through their own company.

"We did the rounds of the distributors in Ireland, and only one was interested. But, as part of our funding, our video rights were sold, so it was no use to them. We raised some private money to release the film and we hoped the Irish Film Board would match it, but they said they couldn't because we were the film's production company, not the distributor, even though we were distributing it ourselves.

"It's ridiculous - they invest half a million in the making of the film, and then they won't do anything to support its distribution. That's been really frustrating. It's difficult enough when we are trying to compete with films on Hollywood budgets."

Undaunted by the many obstacles he encountered in bringing Headrush to the screen, Marcus is preparing his next feature, Souled Out, set in the heady northern soul scene of Wigan in the 1970s.

"Hopefully, it will happen soon. It's a coming-of-age story about two young characters who find this nightclub scene and what happens when you find this world and how hard it is, then, to go back to what you know, to the friends who just don't get it.

"Nearly all the financing is in place now. Jeff Williams, an English writer, wrote the original screenplay and then I did a couple of drafts of it, and now we're working together on the polish. Thankfully, we've worked really well together on it. And it's going to have an amazing soundtrack."

Headrush opens today