Unable to find the ashtray in an upmarket cafe, Jenny Eclair has opted for a plate. She marvels at how much debris accumulates on it within the space of a few moments - a cigarette stub with lipstick traces, some ash, the tuft of cappuccino froth with some more ash dropped in it which she was just about to ingest when her interviewer nervously pointed it out to her. "I am Damien Hirst," she rasps philosophically, gesturing to the little upstairs enclosure from which her smoking has just got us politely expelled. "It's a good job I put my chewing gum in the ornamental chimney breast, otherwise that'd be there too."
There is a thin line between glamour and disarray, and Jenny Eclair delights in walking it. "I am best viewed from a distance," she observes with characteristic self-deprecation "... and at night." The ideal Eclair audience consists of "transsexuals, runaway teenage slags and gin-sodden divorcees", but if these social groups are unavailable, anyone with a sense of humour will do. On a good night, the crowd will leave not merely entertained, but verbally debauched. On a bad night - and a Perrier Award is no insurance against what Eclair phlegmatically terms "dying on your arse - you'll be mentally kicking yourself round the stage; even though the words of the set are coming out, you're saying the most awful things to yourself in your head."
Jenny Eclair has got better lately at dealing with people not liking her. Perhaps partly because her rogue female persona - "An alleycat with delusions of grandeur" is how she describes it, "slinking through the dustbins in leopardskin and high heels" - has over the last few years become more and more defined from her everyday self. Her car stereo has "Eclair" tapes and "Jenny" tapes; her wardrobe has "PVC pants at one end and nice Marks & Spencer's woollen trousers at the other, with a grey area in the middle".
Interspersing sips of coffee with a Diet Coke chaser, she describes herself as "probably the least over-achieving of three horribly competitive, rather workaholicky children". Her siblings are both barristers now, and Eclair's Edinburgh triumph was not her family's first taste of high-profile prize- giving. When her dad (a Major in the Army) went to Buckingham Palace to collect his MBE, Jenny went with him. "I wore a corduroy Donny Osmond hat," she remembers. "I've got a hat face." A solemn pause follows: "My mother always said I've got a hat face."
Her family moved around a fair bit when Jenny was little, though she freely admits to exaggerating the number of schools she went to in the interests of biographical resonance. Mostly they lived in Lytham St Annes, the posh end of Blackpool, and Jenny went to a girl's grammar school which she describes as "very brown knickers. Everyone had crushes on the two male teachers, even though they had lichen round their flies."
After drama school in Manchester, she took her first professional showbiz steps in an "alternative cabaret" outfit called Kathy Lacreme and the Rum Babas. When the band broke up, Jenny fulfilled their remaining engagements as a punk poet, and caught the eye of some businessmen who wanted to turn her into a pop star - Manchester's answer to Toyah Wilcox. "There was one problem," she recalls cheerfully, "I can't sing." That didn't stop Toyah. "It didn't stop lots of people, but I couldn't cope with the guilt. Unfortunately, by the time the guilt had really raised its head, 25 grand had been spent, so I ran off to London to become a waitress."
The turning point in Eclair's long slog from waitress to resting comedy actress to award-winning comedian seems to have been the moment she moved from the sisterly agency she shared with French & Saunders, Ruby Wax and Sandi Toksvig - "hoping for their old bones" - to the testosterone vale of Avalon (home to Frank Skinner and David Baddiel among many others). She seems quite happy to be the lone female on the books of an organisation for whose profile the word "muscular" is widely deemed to be an understatement.
"I adore them", she says, "because they play the game so well - the reality of going up and down the motorway, playing to six people, is very mundane, but when the pantomime is done properly ... well, I can almost believe the car which is taking me to Manchester this afternoon will be a bullet-proof limo, even though it'll actually be a Ford Orion." For corporate gigs, they also supply her with a bodyguard ("They're paying quite a lot of money, so they want to take your skin off and hang it behind the door.") Tonight, though, is a student function. These bring their own problems: "The generation gap is enormous now - I keep thinking some of them might be my children that I've given up for adoption."
While Jenny Eclair is up North corrupting the innocent, Phoebe - the six year old daughter she didn't give up for adoption - will be safe at home in Camberwell. "That is why I took this job," her mother affirms triumphantly, "because it gets me out of the house at night-time and my boyfriend can't come with me because he's got to baby-sit."
By her own admission, Eclair has "a very cliched view of fame: all maribou feathers and relaxing by the pool," but she is under no illusions about success now being served her on a silver platter. "I've got this horrible feeling that I'm one of those people who'll always have to flog their guts out to get anywhere. Things have got to the stage where people are saying `sit-com, chat-show', but they aren't saying `go away, learn your lines and turn up on the night', they're asking me to go and write them."
She is determined to "get TV right" after a couple of less-than-successful attempts. Radio comes first though, in the form of a five part comedy drama called On Baby Street, which she's co-written for Radio 4 with her best friend Julie Balloo, and whose cast list includes Keith Allen ("a sweet boy - very well-behaved") and Kathy Burke. "It's about three pregnant women," Eclair explains, "their stories are related by me - I'm mother nature, just pulling strings and knitting stretch-marks over the thighs of women."
She seems greatly to relish physical decay, especially female physical decay, and rarely seems happier than when talking about Nembutal overdoses or beautiful blondes drinking themselves to death. "I think it's because I always wanted to be an actress," she says cheerfully, "and that's what tends to happen to them." Is that why she preferred not to unwrap her Edinburgh bouquets? "Once you take the cellophane off it's just a bunch of flowers in a vase, but if it's still in the cellophane - even if it is rotting - it's still a bouquet."
8 On Baby Street starts next month on Radio 4. Jenny Eclair plays Her Majesty's Theatre Haymarket, 0171-494 5500, 29 October, and a video of that show will be out in November