This is a personal apologia, of course: her novels, too, are playful, extravagant, artificial and contrived. Like opera, her writing tends to be sublime or bathetic. And her defence of opera is a defence of her own artistic project. When she says, of opera, that, "it isn't ugly, it is rich and beautiful, and rich and beautiful are now seen as completely decadent and not what you're meant to be", you can't help feeling she's talking about her own work.
Accrington's ugly, she says. "When I went back there recently, I looked and all the cobbled streets had been tarmacced and, even worse, they'd taken up all the York stone pavements, so they've compounded ugliness. It was never a picture-postcard place, Accrington, but it had a reasonably harmonious architecture. Now, it's abysmal."
I get thoroughly depressed, I tell her, by what seems to be the slow shredding of the English language all about us. Press releases from prestigious publishing houses now routinely come with grammatical errors. "I do worry about that," she admits. "It does appear to be truth rather than paranoia that there is a shrinking vocabulary - now around 200 words, which is about what you have when you're five. That is scary, and entirely a product of bad television. For ordinary people such as myself, growing up in a Northern town, you would have diversity because you had the language of the King James Bible. People think it's completely old-fashioned, but it's allowing the mind to hear different kinds of rhythms, sentence structures and words, and I think that's wholly beneficial."
In the past, and, of course, in her brilliant debut novel, Oranges Are Not the Only Fruit, Winterson has been scathing about her Accrington upbringing, adopted into a family of Evangelicals. But there are signs now that she's mellowing. When I ask her what qualities her religious background has left her with, positive and negative, she replies: "You know, as I get older, the negatives seem to drop away, and I think what's left is wholly good. Because there's no anxiety any more, no pain, no pressure. What it did give me at the time was enormous self-confidence to stand against the world, because you are a child apart! So that's quite handy if you're going to push yourself out into the world at the age of 16. That's what happens in the faith: you are separate, you are called upon to do something different. So when things started to go wrong for me in the middle years, it was easy to bear."
Was her rebellion against her parents accompanied by a loss of belief in God, I ask.
"No. Never. I cannot lose that sense of God. I'm not religious nor would I seek to be. But I suppose it's about transcendence. It's because I am convinced of the invisible world beyond the material that I write the way I do. I'm not either a materialist or a humanist, because I am sure that there are other forces at work, inside and outside, whatever you call them, that are much bigger than this."
She has one of London's most beautiful churches at the end of the road, Hawksmoor's sublime Christ Church. "I go and sit in it, yeah, but I can't go to services because it's been taken over by the happy-clappies! If you had something that was a little bit higher, people round here would go, but they don't because they're disgusted with its intellectual incapacity. It's all just gush, nobody wants to sit down and listen to all that."
On 11 September, Winterson was in an isolated hut with no heating or water, with the director Deborah Warner, hacking away at her last novel, The PowerBook, carving it into play-form for the National Theatre. "September 11 was the day we left: if it had happened at the beginning of our stay, we wouldn't have known for weeks. We put the car radio on and thought the world had ended."
Warner, Winterson and Fiona Shaw - it's such an inspired combination, I'm amazed it hasn't happened before now. "So am I, so are we all. As you know too well, people have reputations in the world... Deborah said, 'We kept thinking we'd seek you out, but we didn't because we thought you'd be very lofty.' And I've seen all their work, but I've never gone backstage. You do make incredible mistakes when you think that what you know about a person is what they'll be like. It's very rarely true."
It's the same with her, I point out. When I told people whom I was interviewing, they wished me luck, advised me to bring a flak jacket, joked about having security grilles installed. She has a reputation as a Holy Terror. She looks innocent, until I remind her that she once furiously doorstepped the reviewer Nicci Gerrard. "Yeah, that didn't help, did it? But hell, it was a long time ago. I think a lot of it is Northern plain-speaking. That's had a negative effect. Not so much now, because I have learnt that there's a problem there. But yeah," - she leans forward conspiratorially - "you can't just open your mouth and say what you like down here, can you? People are a bit funny!
"If you meet me, God knows there are drawbacks, but I'm not cold and I'm not horrid. I can't run on negative. At the same time, if somebody goes for me... Holy Terrier, more like! I go nuts if it's my personal life, I always have. I get really angry. A PR person, years ago, said to me: 'Look, Jeanette, you may feel this, but you don't say it, you don't show it; we get rid of them for you.' But I didn't know that in those days."
The interview is at an end, and Winterson is very keen for me to roar off on one of her "bike limos": "They've changed my life!" But Jeanette, I say, I'm wearing a skirt. "Tuck it up round your waist! He'll go slowly if you're frightened." She can't convince me, but insists on accompanying me to the Tube. As she locks up, she points out the original greengrocer's awning folded up outside. She unrolls it on sunny days. "I set up my own pavement café and sit out there with my tables and chairs."
I think I shall take to hanging around Spitalfields as the weather improves. Well, she does make a great Northern cuppa.
From The Independent www.independent.co.uk