Injustice (ITV1, 9pm, until Friday)

JAMES PUREFOY is happy to get back to the present day after a run of period dramas from the TV series Rome to Terence Rattigan’s play Flare Path on stage.

“I didn’t want to hold a sword any more, I wanted to hold a mobile phone,” he says, half joking.

The modern role in question is playing a troubled lawyer in Injustice, a fivenights- in-a-row drama on ITV1.

On the surface, his character William Travers is an ordinary criminal barrister going about his daily business, but as he becomes embroiled in a grisly murder case in which his old mate from university is the defendant, it seems his character is just as murky as his infamous Roman incarnation, Mark Antony.

“I’m very used to playing men who are very extraordinary. William is quite an ordinary man although he does do extraordinary things as we find out. But when we first meet him, he’s just your average barrister,” says the actor.

But William has abandoned the rat race of being a hotshot lawyer in London for a slower pace of life in Suffolk after having a nervous breakdown. Yet he’s still haunted by visions of a young boy and vivid flashbacks to a traumatic event that happened while working in London.

Purefoy won’t reveal what happened to William, nor the nature of these visions – “All will become clear,” he teases – but admits that he really relished the complexity of the role.

“As an actor, you try to piece together the character for the audience, and with William, he’s stopped looking after himself, so my hair is very unkempt, and I stopped going to the gym, and shaving, and all those kind of things which just give the idea that someone is a little bit out of focus,” he says.

A Somerset boy at heart, Purefoy says he related to William’s urge to move out of London. “Although I spent a long time trying to get out of Somerset, which I did by the time I was 18, I love it,” he says. “It’s always a part of me and the place I feel more me than anywhere else on Earth.”

For fans of legal dramas, Injustice comes hot on the heels of BBC drama Silk, which followed the careers of two barristers (played by Maxine Peake and Rupert Penry-Jones) as they battled it out with each other to take become QCs. Although Purefoy donned a wig and gown for Injustice’s many courtroom scenes, and his on-screen wife is played by Penry- Jones’ real-life wife, Dervla Kirwan, the actor says comparisons between the two dramas are unfounded.

“It’s a very different kind of drama,” he states. “That really is procedural drama, this is a thriller set in the world of law, and we see what happens on both sides of the law – but it’s a different genre.”

Kirwan’s character is a successful London publisher who quit to move to the coast with her husband and takes up teaching English to young offenders where she discovers one of the inmates has an astounding talent for writing.

Purefoy’s dream role would be to play a foppish Hugh Grant-type character in a romantic comedy. “I’m a huge fan of Hugh Grant – I think he’s an incredibly underrated actor,” he says.

“Comedy is something that I love doing, there’s nothing like hearing people laugh at a joke. I just don’t think I’ve been given enough opportunity to do it.”

He did a course at mime school before going on to study drama. “We did a lot about clowning, and we studied the great Russian clowns. It’s an art form. What you deliver as a clown is incredibly complex and has to be rehearsed to make it look that ridiculous.”

Sounds like there was a fair amount of clowning around on the set of Injustice too. Purefoy recounts how much fun they had on set, thanks to the director Colm McCarthy insisting on having themed days, when the off-camera crew were encouraged to dress up.

“We had Halloween day and a Wild West day because it’s one of the things that Colm does and it’s lovely. But people were still very respectful of the work – you can be respectful and still wear a cowboy hat.”