She does not look as if she could possibly know what she is talking about. She is pretty, petite and as posh as a cucumber sandwich. Her skin glows and her neat bob shines and when she slips on a hairband and perches behind a typewriter, she is wholly convincing as the temporary secretary she needs to be to make ends meet between acting jobs. And yet, when she slaps on some eye-liner, woofs up her hair, rips off the hairband and whips off a G-string, she is equally persuasive as the Soho stripper she became when she was 20 years old.
Stripping was a means to an end. Six years ago, when she left drama school, Equity cards weren't easy to come by and you couldn't work in the West End or for television without one. Padfield's sister got hers by joining a circus. Fiona, who can't eat a battery egg, decided that stripping was a picnic compared to working with caged animals. She answered an ad in the Stage offering a six-month Equity contract in a Soho strip-club, went along for an audition and got the job.
Her mother tried to dissuade her. Her father, a naval historian, was more concerned with her safety than her morality. 'He would have been more unhappy if he felt I was breaking some principle, like eating factory-farmed food.' Before Padfield started work, her parents turned up with their dog to inspect the club. They were all pleasantly surprised by the 'lovely' atmosphere of the members' only, tie-wearing establishment. 'I'd thought before I went there that I would meet the most gruesome and seedy people. They were generally civilised.'
Calling herself Anastasia (the name that Jo, the stripper in the play, also takes), Padfield soon became part of the club circuit, taking her clothes off at a number of clubs, the majority gruesome and seedy. For a middle-class girl, educated at an all- girls boarding school, it was a fascinating immersion, but one from which Padfield realised she could not emerge unchanged. 'I lost a lot of weight. Stripping is very tiring. A strip lasts eight minutes which is a long time to hold an audience's attention. At first I danced a lot, but it didn't work - I learned to keep as still as possible, moving just one part of my body. That could be electrifying.'
She found the emotional transformation more unsettling. 'I had thought I was a certain type of person, that I had certain values and knew what they were. When I was in the clubs, because I had stepped over certain boundaries, suddenly those limits weren't clear any more. I was approached to do pornography and prostitution - before I'd entered this world it wouldn't have crossed my mind to have touched either of them. Once I was there, because everything was accepted there were moments when I thought 'Why not?'.
'I didn't do it, but it made me realise you can be incredibly complacent about what you think you believe. And I'm glad I didn't do it because I think I would have got lost. But it would be hypocritical to say that stripping is OK and prostitution is not. Basically it's all the same conveyor belt of gratification.'
As time went on Padfield's attitude to the punters became increasingly hostile. 'I think I picked it up from the other girls. Some were very sad and very lost; others were chasing the money or loved the attention. A lot of them hated men. From the start I knew what to do physically - I'm a trained dancer - but not what to do mentally. I could have been a happy, smiley stripper. Then I started to think 'you bastards'.' A problem that neither Padfield, nor the play, can resolve is who in this world is using who.
It took some five years before she felt sufficiently able to distance herself from the experience to write about it. While much is truth, impressions and distortions, Padfield maintains that Strip is a fiction. Initially written from the woman's position, she became increasingly interested in the punter's point of view. It tells the story of a Soho stripper whose involvement with a sado-masochist releases her from her cloying relationship with her father. The language is obscene (Padfield's parents, who are 'allergic to four-letter words', will not be among the audience), the images revoltingly explicit; its strength springs from its refusal to portray the stripper as a victim. Jo is fascinated by her discovery of her sexual power and, to some extent, the liberation she experiences in the sexy, dangerous underworld she is inhabiting. But paradoxically, it is when she feels most in control that she is most vulnerable to pornography's dehumanising effects.
'The play exposes human frailty,' Padfield explains. 'But to get to that point you have to use the pornography of, say, a strip. You have to expose the ugly detail to reveal the emptiness. It's about someone who feels she has no identity, so had to become someone else to find herself. I didn't try to avoid the pornography of the situation - I wanted to write about these people and didn't hold anything back.'
While Padfield does not regret her experience of life as a stripper, she is not entirely comfortable about the play; she fears over-exposure. 'I wrote this, it is about me - it came out of my mind. That's partly why I hate the play and sometimes feel ashamed of it - to have the pictures in my head which created this fiction makes me think 'yuk'.'
She wrote Strip without a single stage direction. And she admits that she doesn't think visually. With the help of Peter James, the Lyric Theatre's artistic director (who is directing Strip), she has given it a dramatic form. The play now intercuts the monologues of a stripper and a sado-masochist with a third figure, the father (loosely based on a former boyfriend), emerging as the most significant of all.
Padfield sent the script to the Lyric, the Bush and the Royal Court and, astonishingly for a first play by an unknown writer, all three invited her in to discuss the project and any future ideas she might have. In the end it was Peter James who picked it up. 'It has a distinctive voice,' he says. 'There was something in the rawness of the writing. Just a description of this twilit area of sexuality would be voyeurism, but it is poking around at a deeper level than describing patterns of behaviour. It lacks structure - it isn't canny - some of which you would wish for, but we are for once using the studio as it should be used, introducing a young author at a crucial time of her development.'
But has James been too readily seduced by the subject matter? Would such effort and expense have been made for a first play by, say, a botanist concerning a twilit pond- world? James laughs. 'If it was a wonderful story, I hope I would have the courage to stage it - but I admit this subject makes it much easier to market.'
Strip previews at the Lyric Studio, W6 (081-741 8701) from 9 Nov; opens 11 Nov