Just the three of us

Backstage at the Playhouse Theatre, Kristin Scott Thomas, Kate Burton and Madeleine Worrall are giggling together like schoolgirls. The three are appearing as the three sisters in Chekhov's play of the same name - also starring Cold Feet's Robert Bathurst (David).

'We open tomorrow tonight,' says Scott Thomas, aghast. 'People have paid money...'

Actors say this all the time, but not Scott Thomas. Three Sisters is her second-ever stage appearance (last year, she played Racine's tragic heroine, Berenice, to rave reviews in Paris) and her first in England. And, despite having established herself as one of our most dignified and best-known actresses on film, she says she's terrified of appearing live before an English audience.

'Acting in French gives me a safety net that acting in English does not,' says the actress, who has lived in France for 20 years. 'I'm very aware that I'm not part of the English theatre establishment.'

Scott Thomas - the epitome of cool English poise - admitting to feeling shaky, a little bit vulnerable? She may rue the day she let slip her anxiety, but it certainly puts one of our best-loved actresses in a newly interesting light.

The choice of play to exorcise her paranoia is a good one: Three Sisters is a classic ensemble piece and this particular production features a fleet of top notch actors. Kate Burton - daughter of Richard - is well-established on Broadway; Douglas Hodge, Robert Bathurst and Eric Sykes are also among the cast.

Both Scott Thomas and Burton are leading lady material, be it in film or theatre, but on this stage they are simply actors. 'It's appalling,' cries Scott Thomas who, perhaps enthused by Burton's straightforward effervescence, comes across as more girlish than expected. 'No really, it's fantastic. Not having to carry the entire weight of something on your own. We're all in the same boat.'

Three Sisters was written more than a century ago, but it remains one of the most popular plays in the western canon. Burton should know: she's appeared in it three times already. For her, the play asks all the big questions - 'Why are we suffering? Why can't we have a different life?' - without giving any of the answers.

But what really marks it out is its four strong female parts, including Natasha, the wife of the sisters' brother, Andrei. Burton and Scott Thomas, who were born in the UK (Burton in Wales) but who live abroad, in New York and Paris respectively, both find the play's portrait of three educated women - desperate to go to Moscow but trapped in a dead provincial town - terrifying. 'It makes you realise how far we've come,' says Burton.

Yet Worrall points out that women today are still confined by their lives in the way men are not. 'Even if it's by motherhood or, conversely, by not having children,' she says. 'There's something very modern about that.'

At 25, Worrall is the youngest and least known member of the cast, yet has more experience of the English stage than Scott Thomas and Burton put together - and in playing the youngest sister Irina, also has the play's biggest part.

She rejects with horror the suggestion that she may have given her fellow actresses advice but, having studied at Cambridge, has a particular academic confidence about her role. 'Irina is the play's illustration board,' she says. 'What she goes through somehow embodies the experience of everyone.'