Actor George Costigan on his trilogy of war novels

"I remember once when I was in London, a kid of about 16 poked his head out of a phone box and said 'You're George Costigan!' That means he would have had to have waited for the credits at the end of whatever I was appearing in. I find that unspeakably flattering!"

He's probably best remembered for his role as randy, adulterous businessman Bob who embarks on an affair with two schoolgirls in the classic 1987 film Rita, Sue and Bob Too, set on a council estate in Bradford.

He's also been directed by Clint Eastwood in the Hollywood drama Hereafter and played Eddie, the philandering husband of Ruth (Penelope Wilton) in the movie Calendar Girls.

TV roles have got meatier as he's got older, he agrees, as he has clinched roles in award-winning dramas including Sally Wainwright's Happy Valley (in which he played brash businessman millionaire Nevison Gallagher, whose daughter goes missing), Line Of Duty, Unforgiven, Scott & Bailey and Emmerdale.

"The TV roles have got meatier but I can be choosier now," he reflects. "If I don't want to do something, I can be a little bit picky. There's stuff I did when the kids' feet were growing because I needed to financially and I recognise that."

He loves working on Wainwright's projects, he enthuses.

"It's called falling off a log. She's such a good writer. She's done all the work and the thinking. Basically you turn up and say the lines in the right order and you'll look terribly good."

Yet he has been surrounded by good writers throughout his career, including Willy Russell and Alan Bleasdale during his years with the Liverpool Everyman Theatre, which spawned such famous actors as Julie Walters, Bill Nighy and the late Pete Postlethwaite.

He's also married to writer Julia North, whom he met while he was at the Everyman, and has himself written plays and collaborated with North on the TV comedy Birds Of A Feather.

But it has taken him nearly 20 years to complete his first trilogy of novels. Last year his debut, The Single Soldier, was published, a love story which begins in the Second World War during the German Occupation of France and sees Frenchman Jacques move and rebuild his home for his loved one Simone to return to after the war.

Costigan, who has lived in France for 30 years, says it was there he was first inspired to write the trilogy.

"We were out mushrooming one day with some friends who took us through an old, dark wood. We got to the end and they showed us a house perched on an impossible hill."

The house, he says, stood in utter desolation with a fantastic view across to the Cathar mountains: "But it was sad. We discovered that at the turn of the 20th century the owner fell out with a neighbour and moved it from a nearby village to this field and rebuilt it there."

The image of him moving it brick by brick in a cart to rebuild it in a field – a feat that took seven years – gave Costigan the idea for the novel.

The follow-up, The Soldier's Home, continues the story, with Simone and Enid – two interlinked stories in one book – concluding the tale. It finds Simone living as a single mother in the US, pining for her French love Jacques, the father of their son, and hoping they can rekindle their love and that she will one day move back.

But as time moves on, so does life. They both form other relationships and, living so far away from each other, their dreams fade.

Costigan and his family originally moved to France because of the Thatcher government, he reveals.

"Kenneth Baker was ruining the education system and we had three children going to secondary school. We took a risk and I was the main earner, but I think my wife had a tougher time than I did raising three children.

"It was hard for our eldest son to walk into secondary school when he couldn't speak the language. But the upshot is that all three of our sons are bilingual. We chose to be European."

These days, he divides his time between home in the Aveyron in southern France and the UK. His eldest son, actor Niall, lives in Yorkshire and Costigan comes over when he can to get his fix of his grandson, Felix.

Living away from England hasn't hindered his work opportunities, though.

"I'm still deeply ambitious," he observes. "The majority of my work is behind me but if you judge this, the best of my work is ahead of me because I've reached the stage where I know how to do my job."

It's not only meaty TV dramas that come his way. The challenging theatre roles are right up there too. He's currently starring in Eugene O'Neill's Long Day's Journey Into Night as the angry patriarch James Tyrone at the Citizens Theatre, Glasgow – so there's no slowing down.

When the play finishes, he'll return to his French home – in his words '27km from the nearest traffic light' – where he relaxes by playing the guitar and piano, writing and gardening.

"I know that when I get home I will be knackered from doing the play, but then my friend puts that into perspective. He says, 'Are you tired? Then get down the pit!' I love to do this job so I really shouldn't whinge. It's pathetic."

Ironically, the longest 'resting' period he's had as an actor was after he got his breakthrough screen role in Rita, Sue And Bob Too. He didn't work for six months after the movie was released.

"The thing you come to grasp in this profession is that there are no rules. There's not an actor in the world who doesn't think, 'I'll never work again' at some point. It's the most paranoid profession."

Born in Portsmouth, he grew up in Salford, Lancashire and has found that a lot of his roles have demanded a Yorkshire accent.

He'll soon be joining Suranne Jones and the cast of Gentleman Jack, Sally Wainwright's new eight-part television historical drama set in Halifax, west Yorkshire, and in the meantime is thinking of writing a whodunnit for his wife.

"It started as a present for Jules - I've written half of it and now I'm getting stuck on the police procedural bit, so it may take some time."

But hopefully not another 20 years.

The Soldier's Home, George Costigan, (Urbane Publications), £8.99