A writer who's hard to resist

A passion for war writing has led Owen Sheers to a West End play, presenting poetry for the BBC and a new film, 'Resistance'. He tells Alice Jones how unearthing raw truth remains his only interest

Riding high: Owen Sheers has just started rehearsals in London for his war play, 'The Two Worlds of Charlie F' (David Sandison)

"It's a bit of a perfect storm," says Owen Sheers, still a little out of breath from his bike ride across town. The writer, 37, has spent the week shuttling between red carpets in London and his hometown of Abergavenny in South Wales for the premieres of Resistance, a new film starring Andrea Riseborough and Michael Sheen based on his debut novel.

In between, he's just started rehearsals on a new play, The Two Worlds of Charlie F, which will be performed by a company of 30 wounded and recovering soldiers as part of Trevor Nunn's next season at Theatre Royal, Haymarket. Meanwhile, he's just spent a week in Wales, "back at the coalface of poetry", giving readings and workshops in his day job as one of Britain's brightest young poets.

The producers of Resistance call their screenwriter a "multi-platform literary star". Sheers wrinkles his nose. "That's a spectacularly ugly phrase. It makes me sound like an app." Unpoetic it may be, but it's also apt. In the 12 years since his debut collection, The Blue Book, was nominated for the Forward Prize and Welsh Book of the Year, the rugby player from the valleys has shown himself to be a versatile talent. It's the "different engines of storytelling" which drive him, he says, whether writing verses hymning rural Welsh life, co-creating a three-day Passion play with Sheen or presenting A Poet's Guide to Britain on the BBC.

Resistance is his first foray into film. The 2007 novel imagines that the D-Day landings have failed and Wales has been occupied by the Nazis. One morning the women of the Olchon Valley wake up to find that all the men have disappeared into the hills to muster a resisting army. It's counterfactual history in the mould of Robert Harris or Philip Roth, but it's rooted in fact. Sheers was working as a tiler in the valleys one summer when he heard about the Auxiliary Units – secret civilian networks which, in the event of invasion, would have formed a British resistance. The stories of local vicars and teachers being primed to spy on the occupying Germans and farmers hiding weapons in underground bunkers, ready to flee their homes to fight in the Welsh mountains, stayed with him. In time, they became Resistance, a war novel which focuses not on fighting, but on the uneasy means of survival open to the women who are left behind. "I was never interested in writing the Boy's Own version of war," says Sheers. "It's exactly that kind of approach that masks what war really is. It's more interesting to work in the more complex territory of where the lines between resistance and collaboration blur. I wanted to use what looked like a Len Deighton-ish hook – occupied Britain – to write an anti-war novel."

Directed by first-timer Amit Gupta, the film features a powerfully restrained performance from Riseborough as Sarah, the farmer's wife torn between her absent husband and the kindnesses of a German commanding officer. It's the bleak majesty of the Black Mountains, though, which steals most scenes. Sheers insisted that the film was shot in and around the borders, where he grew up. When it came to the shoot, he roped in everyone from his parents to his old RE teacher and his dentist to help out with crowd scenes, props, even, in one case, the loan of a horse.

Sheen came on board after working with Sheers on The Passion, a three-day play which unfolded over the Easter weekend in Sheen's hometown of Port Talbot. In Sheers' Neath-flavoured take on the Bible, The Last Supper became pork pies and beer at the Social Club (with music from the Manic Street Preachers), while the Garden of Gethsemane was a scrubby patch of grass on a council estate.

"I was adamant that everything should come from the town itself," says Sheers. "We met a roofer who talked wonderfully about the view over the town from the rooftops. As soon as we interviewed him, we thought 'that's our God'."

Born in Fiji, bred in Wales, and now living in a loft conversion in Hackney, Sheers' writing has taken him from Zimbabwe (the setting for his first non-fiction book, The Dust Diaries), to residencies at Wordsworth's cottage in the Lake District and New York Public Library.

He has spent the last month interviewing soldiers injured in Afghanistan for his new play, which will use the verbatim techniques of London Road and Black Watch to capture the horrors of war and the pain of homecoming. Catch 22 meets Beckett, apparently. He's also been commissioned by Radio 4 to write a long war poem to be broadcast over five days next year. "The main reason I've been writing about war is because we've been at war for 20 years. If you want to send people to war, then do, as long as you realise it means this. Let's not look away from it."

After university, he briefly considered joining the Army – "but it didn't take me long to realise that the way the Army works was never going to work for me. They need to make you their own man." Instead, he immersed himself in the war poets, playing Wilfred Owen in a play at Hay Festival and writing a play about Keith Douglas which was performed at the Old Vic by Joseph Fiennes.

Poetry remains his passion. He began writing at a precocious age – poems about the Big Pit mining museum and autumn, which made his teacher cry. He read English at New College, Oxford, before enrolling on UEA's hit-factory of a creative writing course, where he studied under Andrew Motion, who praised his writing as "sharp, fresh, clear and ambitious". By the time he left, he'd struck a deal to publish The Blue Book – a robust, limpid collection of poems about family, first love and farming life. Still only 25, Sheers got a job on The Big Breakfast as a researcher to pay the rent. By night, he was planning his next book, about a turn-of-the-century missionary to Africa, Arthur Cripps.

The experience, perhaps, was good preparation for Sheers' subsequent career, as television's face of contemporary poetry. His Poet's Guide to Britain on BBC4 was a blustery, rugged hike through the classics. "Poetry is still my first love and the form I want to get better at more than most," he says. "I genuinely think that at the end of your writing life, if you can say you've written two or three true poems, that's a pretty good hit rate."

'Resistance' is released on Friday