Joan Rivers: New York's scalpel wit

It's 4.15pm at the Ritz in London's Piccadilly. Joan Rivers, the veteran New York comedienne, is seated on a plush sofa in the poshest first-floor suite of the kitschy old hotel, with the paraphernalia of English teatime arrayed before her, and a triple-decker cake stand – holding two remaining egg sandwiches of unearthly slenderness – slightly out of reach. The grande dame of the Brooklyn-bitchy one-liner gets to her feet to say hello, and you look into the face of a strange, unearthly creature. It's quite a long way down, since Ms Rivers, at 5ft 1in, only comes up to my waist; but close enough for you to register her face's bizarre triangularity.

You are looking at a beautiful woman whose skin has been stretched, sculpted, flensed and, for all I know, cured like a ham, until her features now form a perfect "V". Her eyes seem to have been yanked upwards and outwards by two teams of straining mustangs, pulling in opposite directions. Her nose, by contrast, has been planed and shaved and sharpened and tip-tilted by a team of cobbler's elves, working in 12-hour shifts. The great arch of St Louis, Missouri would cast an envious glance at the huge brows that surmount Joan's black-marble eyes. Compared to the unearthly smoothness of Ms Rivers' cheek, the complexion of a Dresden shepherdess would resemble the wall of a granite outhouse. Her hair has been flicked and teased and raggedy-streaked into a kind of Meg Ryan flyaway look, the hair of a rich 35-year-old Manhattanite.

Joan Rivers is now 68. She doesn't just "not look her age" – she doesn't look any age at all. Years of plastic surgery, skin treatments, buffs and peels has brought her close to resembling one of the Martians in Independence Day. But she is still, thank God, capable of registering expressions. She laughs a lot, and her husky voice shoots out dry little bullets of conversation that pepper you like buckshot. And she's still more than capable of wowing an audience.

Last summer, the Edinburgh festival was the setting of one of those comeback events that make you believe in the Resurrection. Joan Rivers hit the Fringe audience like a Stealth bomber. Old enough to be the mother of many Fringe performers – and grandmother of most of the audience – she knocked 'em dead in a series of one-hour shows. She picked on three women in the audience, ridiculed their engagement rings, persuaded them to show how they faked orgasm, and invited them to identify the lesbian in the eight-piece band. "Look at this," she said, disgustedly holding up a stage chair with a hole in the seat. "They obviously know how old I am." She bitched about Christians, gynaecologists and the Edinburgh Tattoo. She was a trousers-down smasheroo. And now, she's appearing in London's West End, at the Theatre Royal Haymarket, and wondering if she's crazy.

"Why'd I do it?" she said. "I did Edinburgh because I'd just broken up a relationship after eight years. I said: OK, I'm taking anything that's going. And I love going with young audiences, because the one thing I pride myself on is, my stuff is right on the edge. I'm not the Grand Old Woman of Comedy. And it was such a happy time in Edinburgh. There was nothing that didn't work. They were so bright, we were on the same line every night. Nobody was coming there to judge – 'Are. You. Funny?'.

"I didn't want it to be an event – like the first time I did Carnegie Hall, now that was a horror. [Like Tennyson's brook, Ms Rivers chatters as she flows] They all came, I mean Calvin Klein and Kelly, Ralph Lauren, Blaine Trump and her husband, they were all sitting there, all dressed up, waiting for someone else to say, 'This is funny'. That's why I want real people at my show. I want six gay men in the front row. I want Graham Norton. I want the gays, and the young students and a couple of old Jews."

Was she really nervous? She turned her dark, alien eyes on me. "Look at me – I'm thinking, am I out of my mind? Of course I'm nervous. They can turn on you very quickly. I've seen audiences here not like Barry Humphries, and he's the most brilliant mind in England".

For a dame with such surgically enhanced looks, she can be terribly rude about other women's appearance. In the past, her favourite comic butt, so to speak, was the overweight Elizabeth Taylor. "I was the first to say 'The emperor has no clothes'," says Rivers. "I saw her doing a shoot for People magazine, and I said, 'My God, she's a house!'."

Joan used to describe parties where, "Liz Taylor was there in her Orson Welles designer jeans". These days, her victims may have changed but the vitriol still flies around. "Monica Lewinsky? I'm out to destroy her. What happened to her? She's gotten fatter, thank God. She's still around, doing very well working for some pocketbook company. It kills me. If I'd known that by giving oral sex to the president, you could get your own handbag company, I'd have had a whole different life."

We consider in silent awe this fast track to the leatherware industry. Anyone else? "Chelsea Clinton I really don't like at all. And Donatella Versace, another pretty face. She has a face like a piece of leather. You want to open her mouth and put your keys in it..." And she is hilarious about Cher, who, Rivers claims, "just cannot move her face. 'Hey, Cher, you won the Academy Award'. Mask-like expression: 'Hurray'. 'Hey, Cher, your mother died'. Mask-like expression: 'Boo-hoo'."

But Joan, how hypocritical are you being, when everybody knows you've had your own face, ah, surgically enhanced? This is the signal for a passionate Rivers speech about the wonders of Botox and how every woman should get her brows and cheeks injected at the first sight of crow's feet. "It's terrific," she says. "Of course British women would look much better if they did it. What, you want to have a big wrinkled forehead? Or would you like a nice, smooth, gorgeous forehead? It's your choice. So go wrinkle like a prune!"

But if you lose the ability to frown, doesn't it remove one expression of emotion from your repertoire?

She considered. "Well – you could still frown in your heart."

How do you express disapproval? Abruptly, she slapped my wrist. "There!" she said. "Bad person!"

Could she still raise an eyebrow? "I can do everything."

It's hardly surprising that Ms Rivers is such a proselytiser for the skin trade, since she's put her name to a rage of skin-care products called Results, with "a special ingredient called Cosmoderm 7, invented by this idiot savant scientist. It's certainly gonna help you if you can't afford a $600 peel at a dermatologist". Hadn't she heard Robert Redford's recent attack on the Hollywood "nip-and-tuck brigade", and his assertion that he's happy to get wrinkles in a characterful way? "Yeah, but I don't wanna look at him any more in a movie. He looks terrible. It makes me sad to see him like that."

She sounded genuinely in pain, and she suddenly got serious. "Our celebrities, if they're the same age we are, if they look good, we feel good. This may sound really sick, but we owe it to the public. I love Joan Collins. If that's what you look like at that age," [Joan is exactly the same age as Joan Rivers] "my God, that's OK. But I don't want to see Rosemary Clooney. I'd be terrified to see what might come out from under that kaftan she's always been wearing since she was 50."

The sisterly Joan was born Joan Molinsky in Brooklyn in either 1937 or 1933, depending on whom you believe. Her parents, Meyer and Beatrice, were Russian. "A very upwardly mobile family, very educated. My father was a doctor. My older sister was the youngest-ever graduate from Columbia law school at 19. I was very smart, too. If I'd said I wanted to be a brain surgeon, they'd have said, 'Fine, what a good idea'. But when I said I wanted to be an actress, they were not happy. Luckily, they both lived to see me be successful. If my daughter said to me now, 'Mom, I wanna be a puppeteer', I'd say, 'Darling, be the best puppeteer – and marry rich. Marry the richest puppeteer in the business. If you're going to marry a mime, make it Marcel Marceau. Because he could give you a big [she waves her hands to mime bigness] ring [she mimes a huge circle]'."

Too shy to make it as a straight actress, she turned to comedy. "I was such a tender thing to be acting. I couldn't push myself. But comedy meant nothing, so I was able to go out and be funny. And you learn your craft, through seven years of starving and working in strip joints and Greenwich Village clubs. By the time I hit TV, I was ready. Some kids today, they hit too early. They have one or two shots at it and they're finished. But I had enough material from seven years already. So I did OK."

She is so New York, this tiny, slender, husky, rambunctious, endlessly optimistic woman who is so irresistibly rude about everyone, and who makes a cool $25m a year flogging chunky faux-amber jewellery on the QVC cable shopping channel, like Bridget Jones's mum. She's so New York that her taped voice used to be heard in yellow cabs, reminding passengers to take their belongings with them and get a receipt. She's a huge fan of Rudolph Giuliani, who was in London to collect his honorary knighthood on the day Joan and I met. "He follows me everywhere," she says. "I begged him to stop. I said, 'Stop it, Rudi, we've just got to cool it'." Did she think he deserved his knighthood? "He deserves everything. I was in the city that whole time, and he kept the city calm. He just took care of everything. He's a great, great man."

Mayors, she's had 'em all. "When I moved to New York, we had a guy who was never out of his tennis togs. Dinkins, that was him. Ed Koch, he was a good guy, but too liberal. I liked him until he invited me to his house for dinner, and there were these life-size photos in every room." Photos of what? "Of himself. You begin to wonder – is there an ego here?" She admires Giuliani's hard-line illiberalism. "In New York, you have to say, 'You urinate on the street, you're in jail. Next! Your dog shits on the sidewalk, you're in jail. Next!' And that's how he ran the city, and it got cleaned up. He did it brilliantly. You need a Nazi in there."

She's so New York, she turns out to be best friends with two members of the cast of Sex and the City – a show whose spiritual godmother she is. Years before Carrie, Samantha, Miranda and Charlotte starting breaking taboos and saying the unsayable, Ms Rivers was the cutting-edge of intestinal humour. I remember the shock waves that followed her on-screen discussion of contraceptive methods: how she left a coil inside her for months until, "in the end, it got rusty and started picking up Radio Free Europe".

Ms Rivers yelps with laughter. "But that was true! It happened when I was talking to the head of my child's school, and I heard this conversation coming from my crotch! I said a lot of things you weren't allowed to say then. I hope I'm still doing it. But now it's mostly about the human condition. I'm still politically incorrect and I'm happy about that. Because I hate everybody."

Actually, that's not strictly true. The most extraordinary moment of our interview was when I asked about her dog, Spike, who writes a regular column on her website. I'd heard that Spike had died, but the column hadn't. How come? "He was my dog," she said, looking at the floor, "he was there for 18 years, and he had a column, and just because he died, there's no reason why it shouldn't continue". And with that, two huge tears came into Joan Rivers' black-marble eyes. "Look at this," she whispered, as they crept down her milkmaid cheeks.

How can you be so upset, I asked. You – so New York, so hard-bitten, so tough? "Of course I'm upset," she wailed. "He was my best friend in the whole world. Spike – the meanest little son of a bitch. We got on just fine. On the website, on his picture, I put a halo around his head." She scanned my face for signs of levity. There were none. I felt terrible. I'd made Joan Rivers cry.

"And for goodness sake," said Ms Rivers, "don't ask me about my turtle..."

Joan Rivers is appearing at the Theatre Royal Haymarket (0870 901 3356) on 14, 21, 28 April

Deborah Ross returns next week