The Italian job turned out better. Enchanted April, in which she played Lottie, the fey, put-upon wife, and which ran for only seven weeks at the Curzon West End, has now taken more than dollars 12m (pounds 8m) in the United States, making it the BBC's biggest-grossing film. 'It is more popular than Howards End in Brazil,' says Lawrence, who now has a snazzy Los Angeles agent whose name, engagingly, she has forgotten.
Emma Thompson's Oscar can only be good for the Hollywood prospects of young English comediennes. Has the phone been ringing? 'I wish.' But there's a new Radio 4 series with Paul Merton, The Masterson Inheritance, which has Lawrence improvising extended stories around a bodice-ripping family saga from 1760 to the 1890s, and she returns to the theatre, and more bodice-ripping, playing Moll in a musical version of Defoe's Moll Flanders, a character with her own share of ups and downs.
We meet in her lunch break, at the Riverside rehearsal rooms. She wastes no effort on fripperies: no smile, no handshake. She tells me not to sit in one seat because she doesn't like the light there, but in another one that is across the gangway. Then she falls silent. Her dark eyes and strong face are fixed with the same watchfulness as they have on the show's poster. I'd hoped we might improvise a chat, but she looks ready for a questionnaire. More pro than impro.
This is the second time she's been in Claire Luckham's adaptation of Moll Flanders. 'I wish people wouldn't make such a big thing about it,' she says, 'I didn't play Moll Flanders, I was part of the ensemble.' But still it was the same show. 'The last time I picked up the script was eight-and-a-half years ago. When a friend of mine suggested I do Moll Flanders I'd forgotten I'd done it before.' So how has the script changed? 'To tell you the truth I'm not even thinking about the first show. It was one of my first jobs.' Her tone is no-nonsense Brummie. It's left to the director, Peter James, to explain that the early version had anti-Thatcher songs, which have now been rewritten, and fewer production numbers. If there is a contemporary echo this time it's the recession. 'People have to struggle to survive,' Lawrence says, 'but it was worse then. If you didn't have a husband or couldn't get a dowry you were up shit-creek without a paddle. I'm 33 now, and I've never had a husband (she lives with her boyfriend in Hackney) and I'm not starving.' The ad she does for Munchies would see to that on its own.
Brought up in Cradley Heath, Birmingham - her Dad worked for British Leyland, her Mum was a dinner-lady - Lawrence arrived in London after a four-year degree in theatre at Dartington College of Arts. 'It was partly very academic, theatre studies, sociology and psychology, and you took your part ones and your part twos.' But she also did improvisation. 'It wasn't necessarily comic improvisation. A lot of it was used to devise plays and workshops.'
It was during one of her first jobs, playing a manic-depressive Glaswegian housewife in a play called Songs for Stray Cats, that she joined in a late-night cabaret with Jim Sweeney and Steve Stein. She found she could do it. 'It's not difficult, impro,' she says, and spells out a few of the basics. You mustn't be embarrassed or the audience will be too. ('The other week I said to Paul Merton on stage, I can't think of anything to say, and that got a huge laugh, and we went on to the next thing.') You can't be competitive because impro is about trust. You can't go on stage with an idea of what you're going to do as the other person won't have a clue what you're up to. Overall, 'the best thing to do is not even think about being funny'. Simple enough, but few people can take the loo-seat or the feather duster from Clive Anderson with quite her sang-froid, her slow-moving unconcern. She won't be caught courting our affections.
The Masterson Inheritance takes off from the studio audience's suggestions and the studio technicians' improvised effects. 'Sometimes you get the scream before the whiplash.' While she admires the ground-breaking impro-comedy of Americans Mike Nichols and Elaine May (one later directed Dustin Hoffman in The Graduate, the other in Ishtar), she likes to think that the six-part series has a touch of some other Fifties comedians. 'I don't want to compare myself with them, because they're my heroes, but it's got a Goon quality to it because you don't know what's coming next.'
There will be no second series of Josie, though writers did receive commissions for sketches. It fell victim to Hype'n'Backlash syndrome; though watching Channel 4's tape of the best bits one wonders grimly what the rest was like. 'A friend of mine said no one took any notice of their first series,' she says, wistfully, 'so they came back again and again, and when they were into their third series they were noticed.'
'Moll Flanders': Lyric Hammersmith (081-741 2311) to 22 May. 'The Masterson Inheritance': Radio 4, Thursday, 6.30pm.