It requires balls to don a sofa's worth of padding and play Waynetta Slob - the shellsuit-and-Silk Cut-toting slattern from Harry Enfield and Chums. "It does take courage," confirms Sophie Clarke-Jervoise, the show's producer. "Most actresses want to be seen at their best. Kathy is very unvain about the way she appears."
This is one reason why she has developed into such a hot property: the performance always comes before the image. The Independent on Sunday has called her "the best British character actress of her generation", and colleagues gush like geysers about her.
"Her face is very chameleon-like," observes Clarke-Jervoise. "She can take on a character and just become that person. On set, your eyes are immediately on her, even if the camera is not."
Harry Enfield grabs the eulogistic baton. "She's a natural - and not just at comedy. She's loveable, she's got people's sympathy. The thing about her is that you feel for her. If you don't like someone, then you can't find them funny. There are so many people who are in love with Kathy - including my dad. He's excited about me getting married because it means he'll get to meet Kathy at the wedding." Producers, too, are trampling over each other in the rush to meet her. Clarke-Jervoise thinks Burke should have her own series "immediately".
Sitting in her Islington maisonette, last week, supping a bowl of soup, Burke is refreshingly unaffected. She seems unconcerned by the metaphorical rapping on her door. "I get offered stooges in sitcoms and Waynetta lookalikes," she reveals. "But it's silly to do the same thing again. There's enough time later to do something like the Yootha Joyce part in George and Mildred."
Dressed down in sweatshirt, jeans and Dr Martens, she could self-deprecate for Britain. "When I met Isabella Rossellini on a film set," she recalls, "I swear to God I turned into Perry [the tongue-tied male teenager she plays on Harry Enfield]; I was trying to be funny and was just clumsy. I'm the wrong person for this job. I feel I should be working for the council."
She is similarly modest about her looks. "When you're called a character actress, it's because you're too ugly to be a leading lady," she reckons. "They know you can act, but you can't be seen getting off with anyone. I've always got character roles. I used to be overweight, and I did lots of fat girl parts for BBC Schools. I played the mate of the pretty one. But I didn't mind. The fat ones usually got the best lines, while the pretty ones just had angst about being pretty."
What she brings to her roles is a great sense of authenticity. Enfield affirms as much. "I write very stereotypical characters - like the Old Gits," he says. "Kathy came along and made my writing three-dimensional. As Waynetta, she didn't shout and be revolting as I wanted her to be. She made her sympathetic and naive. That's so much richer. Good actors are funnier than comedians. Hugh Grant in Four Weddings and a Funeral is much funnier than a comedian would have been in that part, because you believe in him. He's not doing an act. Kathy's the same."
Whether as Martha, the dumb victim in Mr Wroe's Virgins, (a performance which won her a Royal Television Society award), Madga, the tough-nut magazine editor in Absolutely Fabulous, Lulu, the 18-month-old fall-girl in Harry Enfield and Chums, or now Sharon, the abuse survivor in Common as Muck, Burke is always grounded in reality. "Neil Dudgeon [a fellow actor on Common as Muck] said to me that I could be asking for a pound of potatoes and it would sound filthy," she says, filthily.
Burke, 32, is proud of her working-class roots; her father was an Irish council worker. She recently wrote an unprintably rude (and very funny) letter to Time Out magazine attacking Helena Bonham Carter for suggesting that "if you're not pretty and you're working-class, you have an easier time in terms of people's attitudes to you."
Otherwise, Burke claims, her background has never been a hindrance. "I've actually found it a help," she asserts. "If someone's casting for a bit of rough, you can't get rougher than me. They know they'll get the real McCoy. I'm a typical common woman. Even if I was crap, at least I'd be honest."
As if her acting wasn't enough, Burke is also a successful writer (her play, Mr Thomas, won a Time Out award) and director (her production of Jonathan Harvey's Boom Bang-a-Bang gained critical acclaim). The world, as her fellow Londoner Arthur Daley would put it, is her lobster.
But if all else fails - an unlikely prospect - she could always turn to playing a character not a million miles from herself in EastEnders. "Maybe when I'm a bit older, I could do a Babs Windsor," Burke says, smiling broadly. "I hope EastEnders keeps on running, 'cause it could be me pension."
Kathy Burke appears in `Harry Enfield and Chums', Tue 9.30pm BBC1, and in `Common as Muck', Wed 9.30pm BBC1
KATHY BURKE'S TOP THREE ROLES
1. Waynetta Slob - the pizza-guzzling, fag-smoking mother from hell in Harry Enfield and Chums. Enfield pays tribute to Burke for the development of Waynetta. "Kathy's one of the few people I know who always does my sketches better than I see them in my head. I've got lazy with Wayne and Waynetta. I write less for me now because she's funnier." Burke calls Waynetta "the most glamorous character I've ever played, because she's so self-confident. It's bliss."
2. Martha - the painfully unsophisticated, unspeaking acolyte of a charismatic preacher in Mr Wroe's Virgins. The part demanded nude scenes from Burke. "I can't believe I was brave enough to do it." she says now. "But from the minute I read the book, I understood the character. I didn't feel sympathy for her. I realised that this was all she'd known - that was what I had to keep a handle on."
3. Sharon - the abuse victim, who puts it all behind her and trains as a beauty therapist in Common as Muck. Burke explains: "I liked her because she wanted to start again. Lots of women get involved with someone who's not good for them and don't realise they can escape."
1964: Born at the Royal Free Hospital, north London.
1970s-80s: Trained at Anna Scher Theatre School, north London.
1982: Got big break when director Mai Zetterling came to Anna Scher to cast for Scrubbers, a tough film about a women's borstal.
1980s: Appeared on stage in Mike Leigh's It's a Great Big Shame at Stratford East, and Michael Wall's Amongst Barbarians at the Royal Exchange, Manchester; and on television in Jonathan Ross's The Last Resort.
1990s: Appeared on television in Harry Enfield and Chums (previously: Harry Enfield's Television Programme), Absolutely Fabulous, French and Saunders, Murder Most Horrid, Mr Wroe's Virgins, Jackanory, After Miss Julie and Common As Muck
1990: Burke's debut play, Mr Thomas, performed at Old Red Lion, Islington, won a Time Out award.
1995: Directed Jonathan Harvey's Boom Bang-a-Bang at the Bush Theatre, London.
1996: Appeared in Gary Oldman's (as yet unreleased) slice of London life feature film, Nil By Mouth.Reuse content