Not-so naked ambition

One thing is for certain: being cast in a David Hare play at least ensures that Indira Varma won't have to take her clothes off. Oh God,' she says, rolling her eyes. At the beginning of my career casting directors were like, If you put on another Asian accent, we could cast you in this. If you lose a bit more weight, you'll be perfect for that. Oh, and you don't mind taking your clothes off, so we can give you this role.'' I thought: this isn't what I had in mind.'

Blame Kama Sutra: A Tale Of Love. Varma's very first role was in Mira Nair's 1996 sultry slice of celluloid erotica, a part that required a degree of nudity. She was 21 and full of idealistic enthusiasm about embarking on an acting career, only to have every notion she had about it thrown rudely out the window.

'You aspire in that young naive way to do all the things you've learned about the power of language at drama school, and then you're handed a film script and you go – oh my God,' she says. 'The writing – it's so clichéd. Actually, I don't even understand what this film is about. So yes, at the time, I was terrified. But doing that movie also made me aware early on that I didn't want to be typecast.'

In fact, Varma's heady baptism by fire reaped significant professional rewards: she went on to appear opposite Sharon Stone in Basic Instinct 2 and has established herself as a fairly regular TV presence, with a notable appearance in the BBC/HBO series Rome.

At the same time, however, she's been quietly carving out a career on stage, working alongside some of Britain's most interesting artists – in particular Harold Pinter, with whom she has worked four times.

Now 34, she is appearing in her biggest stage role to date in Hare's new play The Vertical Hour, which first appeared on Broadway in 2006 in a production starring Bill Nighy and Julianne Moore. Varma plays Nadia, a young US academic and former war correspondent who passionately supported the war in Iraq and who fervently believes that idealism is of no use without action.

'It sounds appalling but I didn't really know Hare's work before this,' confesses Varma with endearing candour. But this part is enormous. Nadia is so complex and intelligent; she has a sense of the historical and political context for things that I feel my generation simply doesn't have.

'I was completely against the war in Iraq, but this play has really made me question the alternatives.'

The Vertical Hour closed early in New York, partly because of mixed reviews – US critics (and some British ones) found it didactic. Yes, with his customary eloquence, Hare dissects the gap between private thought and public action, individual conscience and collective responsibility, and, of course, British and US attitudes towards the war, in ways that feel overtly schematic and polemical. But Varma defends it passionately while pointing out that it appears at the Royal Court in a completely new production.

People dismiss it as an Iraq play, but it's about so much more than that,' she says. 'It's about not running away from the person you aspire to be. At one point, Nadia accuses Oliver [the English father of her boyfriend] of having ideals but doing f*** all with them. And that struck a chord with me because when I was at sixth form, my friends and I were full of causes. We were always running marathons raising money for CND. And now we don't, and I wonder where all that energy and idealism has gone.'