The Cranford star talks Morris dancing, prosthetic tummies and marriage to Emma Thompson…

Tell us about your latest project, the mockumentary Morris: A Life With Bells On, which airs on Blighty this Saturday
“It’s like a Morris dancing version of This is Spinal Tap. It’s a documentary-style comedy about a group of pioneering Morris dancers. It’s very daft and hilarious, but because the writer was brought up by Morris dancers, it’s also heartfelt and very moving. I play Miroslav Villandry, a slightly gay American philanthropist with a ponytail, a paunch and coral-coloured jumpsuit, who is awestruck by the sheer masculinity of the dancers. He wants to take them to the next level: extreme Morris.”

Did you have to gain weight for the film?
“I couldn’t because I was filming Cranford at the same time, so I had to wear a prosthetic tummy. One day, they forgot to bring it along; I just tied a jumper round my stomach and no one seemed to notice.”

How has your career changed over the years?
“I suppose I originally got roles because I looked the part carrying a girl through a cornfield. But recently I’ve been playing psychopaths. I love dark roles. They are a lot more interesting than your straight, square-jawed hero.”

Are you very ambitious?
“Just after I started acting, my best mate drowned and that made me think about what’s important. For me, that’s living in the here and now – being with my family, or walking in the hills. It’s not necessarily going off and filming.”

Is it true that a clairvoyant predicted you’d meet your wife Emma Thompson?
“A friend of mine, who’s a witch, told me I’d meet my wife while working on Sense and Sensibility. But when I arrived on set, the only single girl was Kate Winslet and I thought, ‘Well, she’s lovely, but she’s not really my thing’.”

Does your daughter Gaia want to become an actor like her parents?
“Well, she recently appeared as an extra with her mum in the new Nanny McPhee film. You can just catch her as an evacuee wandering down the street.”

What’s the worst job you’ve ever done?
“I was once a very bad tour guide for Americans in Europe. I used to make up historical facts and would sometimes leave people behind.”

What’s next for you?
“Emma has written a film about the marriage of John Ruskin. I’ll play the part of Ruskin with Carey Milligan as his wife. We just need to finish raising the finance then we’ll start filming.”

*Morris: A Life With Bells On screens on Blighty on Saturday, May 29