Best known for her Bafta-winning role in BBC1's Bleak House, 31-year-old Anna Maxwell Martin is playing Isabella opposite Rory Kinnear in Measure for Measure at the Almeida, London (until 10 April). Following the birth of her first child, she returns to our screens on Tuesday in the BBC4 drama On Expenses, in which she stars as journalist and campaigner Heather Brooke, who fought for years to expose the MPs' expenses scandal.
Tell me about Measure for Measure
It's a very sexy play given a modern staging. We've created a dark, sinister world where vice has run rampant. The Duke's method for improving things is to disappear and come back in disguise. Gordon Brown could take some tips from that.
Do you think it's still relevant today?
Absolutely. It's about ego and corruption of power. And sex, which is a huge theme in the play, is everywhere in modern life, particularly because of the internet.
Is this your first professional Shakespeare role?
Yes, argh! The vocal agility you need is huge. But I'm loving playing Isabella. Because she's a nun you instantly label her as such but at times she's very unmerciful, almost fundamentalist, and trying to repress her own sexual burgeoning in a very sexual world.
I've read that you had religious parents. Did you draw on that to play Isabella?
My father was from Northern Ireland, and coming from somewhere like that your faith defines you. That's something we don't really understand outside Northern Ireland, but because of my parents and grandparents I've experienced it.
What's it like working with Rory Kinnear?
I'd wanted to work with him for a long time. He's an extraordinary Shakespearean actor. He's a bit of a giggler though. Well, he's like a cold snake, he remains stoic but makes everyone else giggle.
What drew you to BBC4's On Expenses?
Playing Heather immediately appealed. She's a strong and opinionated woman who knows exactly what she wants and goes after it with dogged determination. I played crying people in corsets for a long time but I went into acting to be a character actor.
What's your take on the expenses scandal?
I'm quite cynical about politicians – they all tend to occupy the middle ground these days. So the scandal didn't hugely surprise me. It was quite shameful that we'd all accepted that they [made false claims], which we had really. Maybe it's Heather's American side that made her ask "Why do you all accept this?"
How are you finding motherhood?
It's wonderful. Every day is like Christmas Day. It's sometimes incredibly difficult being a working mum though. But I've got a very good boyfriend [director Roger Michell]. He's a great housewife! It sounds harsh but there's no point me sitting at work pining for my child. My other passion, aside from my family, is working.
You met Roger working on Honour at the National Theatre in 2003. Would you work together again?
Roger is the best director I've ever worked with and I'm his number one fan. So in that way I would love to work with him. But then in another way it's difficult. His work isn't autobiographical but it's drawn on his own life, so it would be weird in some ways. Plus I'm quite bossy. I'd probably do his head in; he'd be like "Shut up, love!"
What's your dream role?
I'd love to do A Doll's House and to have a go at Lady Macbeth. Although now I feel a bit nervous naming anything Shakespearean, I might get shot down for this one. I might be totally crap!