The former Lewis star tells Alex Bellotti about playing the revolutionary Charles de Gaulle alongside Tom Conti.

In the aftermath of the Charlie Hebdo and Bataclan attacks, Francois Hollande will have no doubt spent many sleepless nights wondering how to best keep France safe. Throughout history, it has been a question that has divided some of the country’s most senior officials – none more so than in the 1940s, when the occupation of France by Nazi Germany tore a previously close-knit friendship apart.

Having risen up through the infantry ranks of the army, Charles de Gaulle had always been fond of his old commander, Philippe Petain. As a new show at the Park Theatre depicts, however, when the latter used his powers as Chief of State to agree an armistice with Hitler’s invading forces, the fallout between the pair became a bitter four year ordeal that only ended when de Gaulle’s Free France movement wrested control of their homeland at the end of World War Two.

“He’s a funny character because he was faintly ridiculous to the English,” says Laurence Fox of de Gaulle, who he plays alongside Tom Conti’s Petain in Jonathan Lynn’s The Patriotic Traitor.

“It’s quite a challenge because he’s a very complex man and very different, I think, to how we’re taught – or not taught him – in history. So it’ll be interesting for audiences to see what sort of man Jonathan depicts him as from his research.”

Eventually becoming president of France until his resignation in 1969, de Gaulle is best remembered for his political nous. A fierce opponent of France’s 1940 deal with the Nazis, he led a government in exile from London which, through a series of revolutionary broadcasts, gained popularity back home and eventually helped the French Resistance in assisting the Allies.

In Lynn’s production, de Gaulle’s public image sits alongside his personal side; in particular, Fox’s scenes with Conti (“so talented it’s slightly intimidating”) show a friendship trampled by contrasting ideas of how to save France.

“It’s interesting that an English dramatist is doing it,” admits Fox. “You would have thought there’d be a French play on it already, but apparently not.

“It’s an amazing relationship; I tend to play what’s written on a page rather than go and agonise for months over research – the writer and directors do that. But on the page, it’s a very warm and loving relationship which sours terribly and it’s incredibly sad.”

Despite finding television success as Detective Inspector James Hathaway in ITV’s Inspector Morse spin-off, Lewis, Fox remains in many ways the antithesis of the ‘actor’s actor’. Respectively the son and nephew of actors James and Edward Fox, he sees himself as reflective of a generation that settled on careers later in life – before he enrolled in RADA, he admits to “just messing around for a couple of years, working as a gardener”.

His approach to preparation is similarly laissez-faire; despite the historical subject, the 37-year-old is loathe to read much beyond the script. “Whenever I research anything I get worse at it. For some people it helps, it just makes me dreadful.”

So he won’t be bringing the character back home to wife Billie Piper and their two sons? “Ultimately your job is to entertain an audience and tell a story, so it depends. Some actors fall on the side of the fence where they want to know that character inside out and want to be them all day, and others just want to turn up and do it.

“But I do find myself behaving quite de Gaulley in other things I do at home. You just can’t help it because you’re like it all day; playing some blunt and uncompromising man naturally makes you more blunt and uncompromising.”

There is no doubt that Fox is nothing less than committed to his craft, but perhaps growing up among actors has lent him such an obvious sense of detachment from its pretentions. “It is just a job,” he insists, adding that his upcoming schedule will in fact be dominated by the release of his second solo music record, the folk-indebted Holding Patterns.

“There’s nothing more boring than an actor talking about acting,” he adds. “It’s a job that you aim to do as well as you can, but I don’t sit around chewing on it, it’s not my life.”

This extends to the way he juggles it with his wife’s own acting commitments. “We just make it work; it’s hard, but we get a bit of help when we need it and we just do our best. It’s not a great job for knowing what’s happening next, so you just have to do your best to roll with the punches.”

The Patriotic Traitor runs at the Park Theatre from February 17 until March 19. Visit parktheatre.co.uk