Julia Davis saw a repeat of her sitcom Nighty Night on BBC3 recently and hated it. "I had a really horrible experience. I thought it was just awful. If you didn't have a sense of humour, you would think it was horrifying." This is undeniable: if you took Nighty Night straight, its misanthropic vision of humanity would make Ingmar Bergman at his bleakest seem as filled to the brim with girlish glee as HMS Pinafore.
The first episode starts with the least alluring speech in sitcom history. A doctor tells the husband of the sitcom's monstrous anti-hero, Jill, that he has cancer. "I'm afraid it's not good news. The lump we removed was malignant." The last episode ends with Jill using her chilly sexual wiles to lure a twitching mess of a man she met through a dating agency to kill himself.
In between, she fellates that same male mess on condition he will pay for her husband Terry's funeral. Terry, cured of cancer, leaves hospital in episode five only to find his tombstone in the churchyard dominated by a hotsy-totsy picture of Jill and the phone number of her beauty salon. She tries to kill Terry and succeeds in bumping off her vicar. Jill gives a neighbour with MS a book called Celebrating Celibacy as a birthday present while trying to seduce the woman's disgusting husband (Angus Deayton).
It's hard not to think about Davis, who wrote the show and stars as Jill, sitting over her keyboard daring herself to write jokes that would make dockers embarrassed. "I would like to write tragedy; comedy I think is almost a fear of not being able to write tragedy," she says.
What is Nighty Night's body count? "I'm not sure." Let's work it out. There was that woman who was driven to suicide by one of Jill's haircuts. "Yes, but there are others who might survive. In the last shot Terry is coming round after being suffocated. And Linda [the lardy, barmy, goth Welshwoman who notionally works in the salon] could recover too. In the second series I might bring some others back from the dead." And no doubt put them through some fresh hells. Nice touch.
It is hard to see how this sociopathic stuff might be retooled for an American audience as another British sitcom about a poisonously dysfunctional monster, The Office, has been. No matter: it is up for three prizes at the British comedy awards next Wednesday, and, though Little Britain is likely to win best show, Davis is a good bet for best TV comedy actress (she's up against Catherine Tate and Caroline Quentin).
Nighty Night deserves to win the best new TV comedy category, not least because the competition - Doc Martin and Life Begins - is nowhere near as funny. If it loses, it surely will be because Davis's humour is the darkest on British TV, with the exception of shows by one of her great influences, Chris Morris.
What sick, degraded, possibly sexually disturbed person would make this shocking filth, I ask her? One who says her favourite film is Festen and who loves the bleakness of Bergman and Nabokov: "I am very drawn to extremes. I think Jill is the very antithesis of what a woman should be, and that, for some reason, appealed to me. A lot of what I wrote was unconscious - people have said to me since that Jill is like Abigail in Abigail's Party [the Mike Leigh satire of suburban mores, with a monstrous feminine anti-hero] and I loved that as a kid, so that's probably in there. Jill is the opposite of the woman who enjoys cooking and housework."
Is that why Jill is such a lousy and hostile cook, serving prawns in milk to a nauseated vegetarian she wants to dispose of? "Yes. I think the comedy there is about how far people will go in that suburban dinner party world not to complain. Mind you, I am the same. I got shockingly overcharged for a drink the other day and I didn't say anything. I just enjoyed the abandon of being Jill, of being so rude and saying things I couldn't in life."
Are you anything like her? "No. I'm a classic mixture of show-off and someone who can't bear to be spoken to." She blushes when she says this, something Jill would never do. No wonder this rather sensitive-seeming woman hates celebrity's dull remit. "I have a godson who asked me if he could have a photograph to give to his teacher," she says glumly.
She declines to discuss her personal life - marital status, fridge contents, top five sexual positions. Again, not very Jill. "I'm worried about being the sort of person who's not guarded about what I'll say."
Fair enough. For the record though Davis, 38 (father a civil servant, mother a secretary), spent her childhood in the home counties before the family settled in Bath. Later she did lots of different jobs - teacher, financial department functionary, supermarket drone, pint-puller, pianist, nanny. Miss any of them? "I quite miss working in a pub. There's something enjoyable about doing a job and not wondering whether you're funny."
When did you first start being funny? "When I was in the Sisters of Percy." This was that bizarre phenomenon, a West Country improv double-act her and her mate put together. "I used to watch stuff like Chris Morris on The Day Today and Steve Coogan as Alan Partridge and think, 'I could be one of them'." And she was right. She sent sketches to the BBC, which resulted in a Radio 4 series with Arabella Weir and Meera Syal called Five Squeezy Pieces. She later worked with Coogan writing on his touring live show (his Baby Cow production company makes Nighty Night). Then she auditioned to act in Morris's Big Train. "I was in this room auditioning and I thought, 'Who's the posh bloke?' It was Chris." She's worked with him a great deal since, playing "stupid or mad women all the time", but is sad not to have been chosen to act in his new series.
Is it difficult working with the posh male Oxbridge types who still dominate British comedy? "I just feel very lucky to be working with people who have the same sick sense of humour." But nobody else is doing anything like Nighty Night. "It was the old story. There were no really interesting star roles for women, so I wrote it myself."
And when she did, she drew on her earlier life and on monstrous female precursors, such as her beloved Bette Davis. "Most of Jill is an amalgam of women I've seen or worked with in the West Country." The Abigail's Party-style social satire came from observing her parents. "I think my parents belonged to that generation of people between 50 and 60 where their friendships are not very close, that suburban world of tense formality, while I really feel I talk about intimate things with my friends."
She also drew on her religion. Jill, selfish, hypocritical, murderous and vile, is a member of a church group; another character quits sexually sordid suburbia for a religious order. "My upbringing involved going to church regularly. As a child C of E, but later I had a fundamentalist thing."
Are you not happy? "I was at a wedding with some schoolgirl friends recently and they all seemed so lively, and I just thought I've become more inhibited in real life. One of them is an accountant. They were really having fun and I do think me and my friends in the comedy world over-analyse. I used to just watch TV rather than pick it apart," she says nostalgically.
"I have a close friend who's an artist and lives on a barge. It's nice being around other influences because otherwise you get completely insecure."
But Davis does seem insecure - in the way that pretty much every functioning creative person is. She says, for instance, that she prefers acting to writing, and the reason for the preference is suggestive. "It's not just that writing is hard work. It's mental in every sense of the word."
We walk to the hotel room which, unexpectedly, Eamonn the photographer has booked to take pictures. Thank whatever God there may be, he doesn't ask this glamorous woman in her tight clothes to disport herself on the bed. That would only make me remember the last time I saw Davis on a bed: then she was astride her on-screen husband, sporting porn store undies, trying to suffocate him for the last episode of Nighty Night's first series. Not nice memories.
"That was a terrible scene," says Davis. "I tried to suffocate him and he tried to suffocate me and then we fought all over the room. We didn't use much of it because it wasn't funny. You'll be able to see it on the DVD. Steve Coogan said, 'This is shit'. So we had to do lots of re-shoots.
"But even then acting is more fun than writing." And yet right now she is having to set aside the former. She's turned down unimaginative offers to play Jill-like women in rubbish sitcoms, put other acting commitments on hold (a veteran of Love Actually and The Sex Lives of the Potato Men, she harbours ambitions to be a film actor: "I love Magnolia and Christopher Guest films and I'd love to be part of that world"). Instead, she's working on the seven episodes of the new Nighty Night series.
She's finding it hard to avoid some of the pitfalls that, she thinks, made the first series sometimes clunking and crude. Worse, though, writing is proving a terrible struggle. "For my personality, which is prone to be depressive, dark and extreme, it's not good to be stuck in a room on your own." Judging by the response to the first series, though, that is precisely where a lot of people want her to be.