At only 27, Donovan Wylie is up there with the greats of photography. With three books already under his belt, for his latest project he immersed himself in the world of a group of New Age travellers. But this is more than mere fly-on-the- wall

THE OLD Street offices which house Magnum (the photographic agency founded in 1947 and now renowned for its global reportage and social documentary) have a feel of fading paint and peeling plaster; although the agency is the photographers' equivalent of the Royal Academy, able to boast that it's had the very best - Cartier Bresson and Kappa - on its books, it has none of the RA's Burlingtonesque grandeur.

Behind the reception desk, listed alphabetically, are the small rubber stamps used to identify the photographs of the elite band of Magnum members (and therefore shareholders in the agency). Near the bottom is "Wylie". At 27, Donovan Wylie is the youngest photographer ever elected as a member by Magnum (it is a long promotional process from "nominee" to "associate member" over five years; the final election to membership is made possible by the other 40 to 50 members at an AGM). Wylie has already published three books; his fourth, Losing Ground, was published by Fourth Estate this week, and the photographs - of New Age travellers in the early Nineties - will be on display in the National Museum of Photography in Bradford from 13 June.

On meeting, Wylie almost immediately asked me - with more aggression than defensiveness - what I thought of his work. Given its observation of one group's lay-by lifestyle outside Stroud, moving, after the Criminal Justice and Public Order Acts, into squats and slums in the East End, "lovely" clearly wouldn't do. I told him I was surprised how beautiful many of the images were: they seemed timeless, more elemental for all the dirt and the stark, claustrophobic family life. It all looked dignified in black and white. They reminded me very much of Richard Billingham's work, graceless but graceful. He nodded: "And what didn't you like?" I just felt sorry for the children, like the one kneeling inches from the television watching Noddy as a mother, in bed in the background, shoots up.

"A subject tends to create the aesthetic for itself," he replied, "and in this case black and white fitted. I gave them the dignity of beauty because their life is full of life, it's the opposite of lifeless. The children were very strong characters, no mucking about, and they were happy. The parents had a lot more anger: they were forced to live like that. These were people my age, with my concerns, so it was an intimate kind of project. I loved them for being so open with me. I'd never been accepted in that way before. But I didn't really know what I was doing half the time. Talking, hanging out with them and trying to work out what was going to happen next. Every day became a ritual of trying to get money, food, trying to get sorted out."

The photographs were taken over a period of five years between 1993 and 1997, during which time Wylie estimates that he would have spent the equivalent of two years in the New Agers' company. "I could understand their exclusion, their need to separate themselves. Stylistically, I like things from the past. I did this book in a very traditional sense, which suited the subject, because they were trying to get back to a traditional life. I'm frustrated by a lot of culture, and liked their idea of rejecting the modern and going back to the old. But this project is also about the Nineties; it's a new subject."

The CJA is the caesura in the book. The photographs change abruptly after those taken in Gloucestershire between 1993 and 1995; in Whitechapel, Bethnal Green and Seven Sisters, from 1995 to 1997, the images are more usually interiors, full of dirty duvets and ovens, the settings dark and cramped. "The legislation forced them off the roadsides," says Wylie, "and they were constantly trying to find somewhere to stay: squats, disused buildings.

"You have to respond to a lot of ignorance surrounding these people. What happened to them became their greatest protest... they got pushed out and pushed out, to the point where it became a social issue. I lost them after the Criminal Justice Act, and then just by chance I found out where they were, in Whitechapel: it had never been idyllic, but the point was they were trying to achieve something they weren't allowed to do. Those who don't or can't conform are neglected and oppressed by society, and so they begin to oppress themselves. A vicious circle began."

Needles become increasingly evident in as the book progresses. "Their reaction to my photographing them taking drugs was 'so what?' Drugs are such an ordinary thing. Everyone is doing them, everyone. Drugs affected a lot the sights. I always saw Liverpool Street Station [from where he took the train to visit them] as an airport; it was like taking Concorde to some distant world right on the fringes of earth. I found going in and out of it extraordinarily difficult and strange. I gradually I had to pull away, move out."

Born to a Catholic mother and Protestant father in Belfast in1971 ("cool move by them"), Wylie is the youngest of three sons. He says he's now envious to see the city so obviously thriving. "Belfast was never a city I really got to know, because I grew up during the Seventies and Eighties, during The Troubles. I lived two miles from the city centre, where there was this big hill, and I would go to the top and look at the city and wonder 'what goes on in there?' I didn't go in the city until I was nine. Imagine that!"

Wylie has been using a camera since he was ten. Branded a "spectacular failure" at school, he left to photograph gypsies in West Belfast in his teens, eventually producing a book called 32 Counties. Describing his work as a photographer, he says, "all my early 20s were just partying with a camera." He published another book, Dispossessed, about impoverished communities in London, Belfast and Glasgow; and then Picador gave him an advance to spend time in Russia, which gave rise to his Notes From Moscow. "I got by on a dollar a week: living on Mars bars, Lucky Strikes and a pint of grass."

With short black hair and piercing green eyes, he's intense and seemed almost nervous during our staccato conversation. ("I'm terrified of speaking to people like you" he tells me later, in the pub.) But it's hard not to be full of respect for him: he's very political,eloquent on the subject of his art without ever being self-absorbed. "The photographers I like are very much themselves. I don't use any as obvious influences, but I like the early American photographers like Walker Evans; those who took pictures of facts and were intellectual about it. Whereas European photography tended to be based too much on aesthetics, its appeal was emotional; British photography balanced it perfectly. In the Eighties people like Graham Smith and Chris Killip documented industrial decline, and they had a beauty in their images, but their images were facts, they made you think."

His wife (the writer, Candida Crewe) is expecting their first child in July. He speaks in glowing terms about her, and with excitement about fatherhood. "I can't imagine anything I would want more. I'm no longer a young person. I spent much of my 20s just getting wrecked, I've done all that." Wylie is one of those people who is hugely successful without seeming ambitious, doing what he does simply because he's very good at it; it's the photographic equivalent of kitchen sink drama, proudly rooted in reality and the difficulties of the day to day.

"I don't really see myself as a journalist," he says. "All these journalists travel all over the world, and 40 years ago that was interesting, because we didn't know what the world looked like; but now we know everything, but we don't look at anything next-door, we don't look at ourselves. I find it much more interesting to look at the local."