On the morning I leave New York for Toronto to interview Naomi Klein, I pass, as I inevitably do every eight blocks or so, a Gap store. Across an entire display window, the word ''Freedom'' has been spray-painted graffiti-style. Next to it, covering the next window, is the word ''Independence''. I stop and stare, feeling first excited, then mystified. I look more closely. The corner of the letter F is peeling slightly from the window. It is a sticker. And it is not sprayed onto the outside of the window but applied from the inside. But of course. How could I be so naive?

The sticker is part of Gap's new advertising campaign: anti-corporate sentiment absorbed and looped back. I go inside and ask a sales clerk to confirm what it is, not because there is any doubt but just because I am so stunned. ''Oh, the graffiti?'' he says, smiling broadly. ''Yeah, we put that there. Looks cool, doesn't it?''

By the time I meet Naomi Klein, weeks before she comes to the Edinburgh International Book Festival, I don't so much want to interview the writer as say, ''Sign me up.'' As a meeting place in Toronto, she has chosen a cafe that is also a bookshop and salon, the walls covered with fliers about theatre groups, poetry readings and political events. It is the sort of place that is extinct where I live, in New York City. Despite the fanfare about the protests in Seattle last year, the anti-corporate movement in the States is contained in a small to mid-sized media story labelled ''The New Activism''. There the corporate takeover is so complete that it has effectively filtered out the growing din of protest that, in Europe and Canada, is emerging as the definitive political movement of our time.

Klein's 450-page book No Logo - a bracing manifesto that documents and indicts the machinery behind global corporate culture - has been the number-one book on non-fiction bestseller lists in Britain and her native Canada for six months. In the States, the book is, in Klein's words, ''essentially underground''. It was turned down by every publishing house and, when it was at last grudgingly published, it was ignored in the media.

The movement Klein both prophesied and catalysed with the book - which was published just months after Seattle - has exploded into an international mass protest movement not seen in size or velocity since the 1960s. Klein now travels the world and speaks to tens of thousands of people, riding the crest of a cultural tidal wave commonly called ''the anti-globalisation movement''. She has been heralded as ''the face of the New, New Left'', the ''Prophet of the New Politics'', and to her chagrin, ''the pin-up revolutionary''. But does a passing sexist slight matter when The Times hailed her as, ''probably the most influential person under the age of 35 in the world''?

When she walks into the room, she looks like a poised and sharply-dressed thirtysomething. The 31-year-old is pretty, trim and somewhat petite, but when she starts to talk, she belies both her age and her generation with the sheer size of what she is talking about.

Dressed in a low-key but chic denim outfit, and wearing very little makeup, she asks if we can sit by the window, where it's lighter. I have the US edition of her book, which features a curly-haired child in a Gap-like sweatshirt with the words ''No Logo'' in the top right of the

garment. ''I hate that cover,'' she says. ''It's just wrong. The European and Canadian cover is solid black, with only the words ''No Logo'' in white, and I love that. But, in the States, they have this idea that Americans couldn't deal with a cover like that that they need colour and image.'' She laughs. ''Ironic, isn't it?''

Klein lives nearby in a modest house in Toronto, with her husband, Canadian television presenter Avi Lewis, who she was hired to interview for a CBC television programme in 1993. They married in 1998, and he supported her during the four years it took her to write No Logo. They wear no wedding rings, but are by all accounts very happily married. Asked how she has been marketed in different ways in the US, Canada and Europe, she grins and describes a recent phone call from American Vogue. ''They wanted me to go shopping with them,'' she says, her voice laced with incredulity. ''They said, 'This is what we see. A story with the headline, ''Shopping with the enemy''. And I said, 'Well, who's the enemy?' And they said, 'You.' And I said, 'I thought you were the enemy.''' She laughs and shakes her head. ''I'm not doing it.''

Klein is quite understandably reluctant to be a figurehead for a movement that repudiates leaders. Her political pedigree can be traced along the lines of the American left and Jewish intellectualism. Her grandparents were American Marxists active in the 1930s and 40s and her grandfather was sacked as an animator at

Disney for organising the studio's first strike. Her parents moved to Canada to protest against the Vietnam war. Her mother also made a

controversial anti-pornography documentary about the life of a stripper. Klein rejected her family's politics at first and became enthralled with everything that mall culture, labels and teenage consumerism had to offer.

In her book, she writes about being entranced by the bright, seductive yellow of the Shell logo from the back of the family car. This may be where the seeds of Klein's political passions began to take root. She writes of the perils of consumer culture not as somebody immune to its allure or above it, but as somebody who was shaped by it but finally transcended it.

Speaking of consumer lust, she says: ''I feel so oppressed by it because I am really susceptible to it. I am not one of these people that is invulnerable to the seductions of it all. I can't walk around Soho, in New York. But I can walk along Queen Street in Toronto, which is our hippest shopping street and I don't get that feeling that I get in New York or London, where I'm overwhelmed by the design and how the handbags are displayed as works of art.''

Like many children of the hippie generation, Klein developed a distaste for her parents' earnest, lefty beliefs, and the embarrassment it caused her. As a girl in her native Montreal, she fussed with hair and makeup, and spent a lot of time coveting clothes and accessories. She also went through bouts of bulimia. At the age of ten, her mother took her to an anti-nuclear march, and she was furious. Klein said: ''I came back and said I would never, ever go to a march with her again, and that I was not a political prop. I was like, 'You guys are losers. I'm never talking to you again.'''

Klein's teenage rebellion came to an abrupt end when she was 17 and her mother had a stroke. The event broke a dam of held-back emotions for Klein, primarily love. She took a year off from school to care for her mother, and says it was that experience that made her snap out of her self-absorption.

But how do you forge an identity for yourself if you're born in 1970, and every conceivable coming of age path has been rendered cliched? As Klein writes: ''In our final year of high school, my best friend and I passed the time with morbid discussions about the meaninglessness of life when everything had already been done. The world stretched out before us not as a slate of possibility, but as a maze of well-worn grooves like the ridges burrowed by insects in hardwood. Step off the straight and narrow career-and-materialism groove and you just end up on another one - the groove for

people who step off the main groove.''

As political as No Logo is, this crisis in the young Klein may be where

her vision was forged. She found a way for a new generation to define itself in a culture that had already co-opted all definitions. ''Here I am attacking the desire that the media has for easily identifiable, easily packaged leaders and slogans,'' says Klein. ''But then the criticism is I've provided one, that I've become an acceptable face for these things.'' How does she deal with the criticism? She shrugs. ''I have a thick skin. I've chosen this profession and I just try to prove to people that I'm different and they can trust me.''

Klein betrays neither hubris nor bitterness. ''I think that what drives this wave of activism,'' she says calmly, ''is a desire for direct participation and direct democracy. People are not willing to delegate power within the movement to a set of leaders, partly because they think it makes the movement vulnerable since those people can be taken out. But also because they simply don't want to be followers. They don't want to be spectators anymore. And I think that's a great impulse.''

If you haven't read No Logo, you might

suspect it is a knee-jerk attack on corporate

culture, advertising and capitalism. But Klein is an exceptionally good writer and manages to make her subject crackle with originality.

In carefully wrought examples, she unveils not only the economics of the corporate

machinery but the soul of it. Not only the facts and figures of sweatshops but the consequences of a world that has virtually obliterated unmarketed space. Pepsi, Klein tells us, aspires eventually to project its logo onto the moon. The true menace, she says, is not brute force but seduction. Nike doesn't just want to sell its sneakers; it wants an emotional connection with its consumers. Capitalism now wants your mind and soul, as well as your cash. The idea is not to just sell products, but to ''brand'' the

company's name and identity deep into human consciousness.

And so we wake up to a new millennium in which Lenin busts have been pulverised, only to be replaced by an omnipresent Nike swoosh. The swoosh is, as Klein says, only marginally about sports attire. It's about a utopian dream or, as Nike puts it, ''enhancing people's lives through sports and fitness''. According to

Starbucks chief executive Howard Schultz,

people don't just go there for coffee, but for ''the romance of the coffee experience, the feeling

of warmth and community people get in

Starbucks stores''.

''All of this branding - the trade in human emotion that branding represents - is a response to the fact that, as I say in the book, we weren't buying the pitch,'' says Klein. ''People were not staying loyal to their brand. They were shopping based on price. And so this

ideology evolved that, you know, we need to dig deeper. We need to have a deeper kind of connection with our consumers.

''I also think there's a megalomaniacal aspect to some of these chief executives. I have sat down and talked to these guys. They'll say, 'You know, the church had its time, the state had its time, and now it's our time.' And they really do believe that. What people are screaming about is the fact they've seen power delegated from points further and further away from where they live. It's essentially looking at globalisation as a crisis in representative democracy.''

Halfway through our talk, it occurs to me that Klein's ascendance signals the end of an era. She is a woman, she went to a good college, and she is not talking about feminism, identity politics or the finer nuances of sexual harassment. So can one at long last repudiate political correctness and post-feminist feminism without having to explain that one is not a fascist?

Klein smiles. ''It was a bit of a reign of terror,'' she admits. ''I mean, by the time I left university, I was very angry at the censorious tendencies. I felt I was too angry and so did my editor. I have an excellent editor. She forced me to be very extremely precise about what I was critiquing from that time. There was an insularity to it, a sense of blindness and privilege. And it's embarrassing.'' One gets the impression, though, that Klein's anger is tempered by her gratitude for all the rocky roads that made her who she is today. ''I've got a ton to thank feminism for and I'm not distancing myself from it. But what better definition of feminism is there than to say that it can at last transcend its own immediate concerns? That's the real privilege.''

It seems to me, I tell her, that this movement is far more anarchist than Marxist. ''Yes,'' she says. ''It's a reaction against centralised

control. We're seeing a new kind of anarchist theory emerge that I wouldn't even necessarily call anarchist. It's a fight for the right to

genuine self-determination, which dates back to the earliest self-determination movements. So I wouldn't give anarchists all the credit because I think it's way older than that. I met this guy in Prague and he said, 'Under communism, we were treated only as producers. Under capitalism, we're treated only as consumers.' It gave me chills.''

Unlike the activist movements of the 1990s, the anti-corporate movement includes the media in its indictment, but Klein has found ways to straddle the roles of journalist and activist. ''It's incredibly hard as a journalist to cover these events,'' she says. ''Instead of one protest, there's a hundred going on at the same time. It's chaos but it's also quite beautiful.''

Time is up. Klein says she does visit New York occasionally and she'll look me up next time she's in town. She stands up and now she is no longer expected to be Naomi Klein, representative of the New Global Consciousness, but just a thirtysomething woman finding her way, her face relaxes. She shakes my hand, and with a glint in her eye, says: ''It'll be fun. I love New York. We'll go shopping.'' n

Naomi Klein is at the Edinburgh International Book Festival, Consignia Theatre, Charlotte Square Gardens, on August 20 at 5.30pm and August 21 at 3.30pm.