Jennifer Aniston strides into the suite of her central London hotel, just visible behind the protective shield of her entourage. She pulls up a chair, pours herself a glass of sparkling water and is handed a cigarette which she never lights, preferring to roll it between her fingers like a draughtsman’s pencil. Her entourage - Warner Bros executives, Channel 4 publicists, her minder-manager Molly Madden - position themselves strategically around the room, monitoring her movements with fawning diligence. They chuckle as she makes a joke and nod gravely when she is serious. They have the spontaneity of canned laughter.

Aniston has just returned from a cycling holiday in the south of France and is deeply tanned. Her perfect American teeth sparkle brilliantly. Her trademark haircut, the “shag or just-got-out-of-bed-look” as she calls it, is shorter. The Haircut in haircut shock! She is wearing a tight white T-shirt and ripped designer jeans, and looks younger than her 28 years; she could pass for an affluent student, preparing for a summer in London, rather than the global icon she is rapidly becoming. She seems bewildered, but also delighted, by her good fortune.

Since landing, in 1994, the role of Rachel in Friends - the smart, sophisticated comedy set principally in two Manhattan apartments and a coffee house, Central Perk, where Rachel works - Aniston has ridden a magic carpet of renown. Though one of an ensemble cast of six, each claiming equal billing, she is the undoubted face of a show that earns Warner Bros $500 million in annual syndication rights and has a worldwide audience approaching 100 million. She has the hair and the burgeoning fan club - she recently pipped, in a survey, Liz Hurley and Nicole from the Renault Clio advertisements as the woman most British men would like to marry.

In three years, Aniston has gone from being a little-known actress - whose film debut was a slasher flick, Leprechaun, in which she was pursued by an axe-carrying midget - to demanding (and receiving) fees of $2 million for her latest movie, Perfect Picture , and the $60,000 per episode pay rise that she and the rest of the cast of Friends recently negotiated. “It’s a bizarre thing, but the rich really do just keep getting richer,” she smiles.

Her earnings are swelled by her apparent inability to stop endorsing products, from Microsoft software to L’Oreal shampoo. That she continues to promote shampoo baffles: she claims to be “fed up with all the hair stuff”. “I went to the same guy for years and he just cut my hair blunt. But then this one here made me go get a new haircut,” she says, gesturing towards Molly the Minder. “I went to this new guy and I was, like, in shock because he used a razor blade and cut it in the most bizarre style. There was nothing planned about it.”

Molly intervenes: “When you started the show with your old hair it was, like, she’s so pretty and cute but you can’t see her face. So we suggested she see this guy, Chris Mcmillan, who cut it around her personality. Do you agree he did that?” “Oh yeah, Molly, I definitely do,” she says, dutifully.

Aniston, unlike Rachel Green, the indolent, pampered princess she plays in Friends, had a rough and relatively impoverished childhood. Though born in Sherman Oaks, California, she grew up in New York City, where her Greek-American father, John Aniston, worked as a jobbing actor in minor television soaps. Her parents separated when she was young. Her memories of childhood are of “constantly being shunted” between her mother’s Manhattan apartment and her father’s place in New Jersey. “My father didn’t really work much when I was a kid. During my younger years we were pretty broke. It was tough for everyone.”

John Aniston was a difficult man. “I remember once he said: ‘Leave the table, you’ve got nothing to say.’ I was doing what young people do: listening and learning. I guess that’s the kind of man he is: demandingly blunt.”

He did nothing to encourage her ambitions after she enrolled as an adolescent at the High School of the Performing Arts in New York - the school that was the model for the egregious television show Fame. “He really didn’t want me to be an actress,” Aniston says. “He told me I’d never make any money, I’d starve and it would be awful. But that negative input made me want to succeed even more.”

After drama school, she took several small roles in off-Broadway plays while supporting herself as a waitress. When she turned 20, she moved to Los Angeles. She auditioned endlessly and won small, forgettable television roles, in Ferris Bueller, The Edge and Muddle Through - all failures. Then it dawned on her what was holding her back: she was the wrong shape. She had what she describes as a typical Greek figure: “Big breasts and big butt.” She says: “The disgusting thing of Hollywood is that I wasn’t getting jobs because I was too heavy.”

This disturbed her because she had never thought of herself as overweight. “Now I have to watch what I eat, I work out, but I’m not crazy about the whole thing. Really, it’s just a drag, something most women suffer from. The lucky ones are those with fast metabolisms. The rest of us have to work a bit harder.”

After eventually losing 30lbs, she was invited to audition for the pilot of a new show, Friends. The executive producer originally wanted her to play Monica, the freelance chef with whom Rachel shares an apartment, but Aniston was attracted to Rachel, because “she was quirkier and I connected to that”.

She knew from the beginning that the show was something different; that the scripts were sharp and stylish and true. “I think Friends captures that lost period in your twenties when you don’t know where you’re going, or what you’re doing or who you are.”

In recent months, the cast have been buffeted by abuse, prompted, in part, by stories that they threatened to strike over pay. There have been rumours of petty rivalries, strained relations and discord on set. Aniston’s supposedly rivalrous relationship with Courteney Cox (who plays Monica and whose latest film, The Scream , was one of the hits of the summer) is the subject of malign gossip. She was even accused of treating her long-time partner, actor Tate Donovan, “more like a poodle than a boyfriend”.

“You know, the worst thing about all this is that my anonymity doesn’t exist anymore,” Aniston says, declining to talk about specifics. “It’s a strange thing to be watched, talked about and have people making up stories about you. Some of what is written is really hurtful. The good thing is that as a cast we are very close and protective of each other. We’ve had each other to hold on to during this scary explosion.”

That the pay dispute became public angers her, although she denies that the cast threatened to strike. “Look, the show was a big hit and we were at the point in our contract where it was right to renegotiate.”

Molly chips in: “People turned against the kids. Their motivation came from a pure place.”

A pure place? “Yeah,” says Aniston on cue. “It came from a good place and it just became, like, this ugly thing. We felt beaten up. People say that’s what happens: you become a big celebrity, climb your way up and then they rip you down.”

The conversation meanders on for a few more minutes, with Aniston talking about the successful movie career she hopes to forge, before the woman from Warners interrupts: “Time’s up.” Aniston rises, smiles professionally and is led across the room, a small, dazzlingly pretty figure lost in the corporate entertainment machine that is closing around her.