Most women fall into prostitution because of childhood abuse or becasue they've run away.

Kelly is an exception. Nick Morrison talks to her on what she claims is her last night on the job.

KELLY wasn't abused as a child. She never ran away from home, she wasn't taken into care, her family wasn't even 'known' to social services. Kelly is an exception among the girls and women working the streets of Middlesbrough's red light district.

A Barnardo's study of working girls in the town found that 86 per cent had been the victims of childhood abuse, 97 per cent had run away from home or local authority care, and 100 per cent had been 'involved' with social services at some time in their lives.

But if the upturned values which govern her world mean Kelly had an unconventional childhood for someone who sells sex, there is something depressingly familiar about the latter part of her journey into prostitution.

"I had a brilliant childhood - but I got hold of gear," she says, and that explains everything. The same Barnardo's survey found that 87 per cent admitted to using drugs, with heroin predominant.

Kelly is a pretty 20-year-old, although too much of a description would give her away to her family, who don't know where her money comes from. Kelly isn't her real name, either. Far from the traditional image of fishnet stockings, short skirts, and skimpy tops, she's wearing jeans, a woolly jumper and a thick anorak. She needs to - the temperature outside is hovering around freezing and there's not much warmth to be had on the streets.

We're sitting in a camper van owned by Barnardo's Secos project. Secos - Sexual Exploitation of Children on the Streets - was set up to offer help and advice to young people who sell sex in Middlesbrough, but doesn't confine its work to teenagers.

The Barnardo's outreach workers and volunteers said they would try to persuade one of the girls to speak to me, but in the event it doesn't take much to get Kelly to talk. She's articulate and wants to tell the world what has happened to her.

Kelly says she got into drugs through her ex-boyfriend. At least, she says "ex", but it turns out they're back together now, although he's in prison. She couldn't work out why he never took much interest in their son, who's now three.

"I wanted to know why the gear was more important to him than the baby. That is when I had a go. I tried it, liked it, started having it once in a while, then every day," she says, with the matter-of-fact manner of someone who's replayed this story many times in their head.

That was two years ago. She's a trained beauty therapist but lost her job when the drugs took hold, and turned to shoplifting to fund her £80-a-day habit, although that couldn't last. "I got too well known. I couldn't go into town without getting put over the radio by security staff," she says. So about nine months ago, she turned to prostitution instead. "It just seemed an easier way to get the money."

When I met her, Kelly had only been back on the streets for a week. She had given up heroin - doing "a rattle straight", she calls it - for four weeks, but started again when she came back to visit some of her friends. She has done ten rattles now.

"It is the nights that are the worst - every ten minutes seems like an hour. It is like the flu but a thousand times worse: you get all the aches and pains, your body is full of pain, you've got cold sweats, you get the shivers, runny nose, runny eyes, sneezes, no sleep. You climb the walls. I would not wish it on my worst enemy. You don't even feel like death warmed up; you just feel like pure death."

Her habit went down to £10 a day, and she says now she's just dabbling, so it's £5 a day. But she's out tonight because she owes money. "After tonight, it's a new start. After tonight, I'm staying away from here - I've got to get away from here to get off the drugs."

Her £5 habit means she doesn't have to come out often, and when she does, she doesn't have to stay long. She will only do one or two clients in a night, although she has a lot of regulars. "Your regulars can give you £100 - it just depends on what they're wanting."

Kelly's attitude to her clients is somewhat confused. Some of them she obviously knows quite well, and in a business as intimate as hers it is not surprising that the boundary between work and life outside work is a blurred one.

"It is just business," she says, before pulling herself up, "Friends, you are friends. You get to know them, you become friends," before her attitude shifts again, "They treat you nice, but it doesn't go no further than business. They treat you right and you treat them right. At the end of the day, you give them what they pay for."

Girls come to the Barnardo's van for a sandwich and a coffee, to stock up on condoms, most of all, though, for a break from the streets and for someone to talk to. Someone who won't judge them. Kelly has no illusions about what she does. It doesn't mean she's happy about it, but why should she be ashamed?

"People look down on you when they don't even know nothing about you," she says. "It is degrading doing this, I am lowering myself, but at the end of the day I'm not harming no one, I'm not in the way of no one. People know what you do and they just look down on you and they think you're scum before they find out anything about you.

"My friends are all right, but if you pass someone in the street and you are walking up and down, the way they look at you... At least I'm not out having one-night stands, like they do. At least I get paid for it."

She says she regularly gets people shouting abuse as they drive past, the predictable 'slut' and 'prostitute'. It is mainly women who shout, she says.

"They're shouting that when half the time it is their husbands... It doesn't bother me, they don't know nothing about me," she says, although clearly it does bother her, and she doesn't like being called a prostitute.

"I'm a working girl. At the end of the day it is a job. I know what type of job it is. If I was a teacher it might be highly thought of, but it is a job, it is the oldest profession going.

"I use the word prostitute, but it sounds degrading. We're all just working girls. I don't look at it as prostitution; we're just trying to make money. I'm making a living, at the end of the day."

Before meeting Kelly, I had been taken on a tour of Middlesbrough's red light area by Linda Cronin, who works in contraception and reproductive health for Middlesbrough Primary Care Trust, and is seconded to the Secos project for ten hours a week.

As well as the areas I had known about from living in the town some years ago, chiefly streets largely deserted at night-time on the other side of the railway line, commonly known as 'over the border', we also take in a couple of industrial estates and busy roads densely populated with pubs and restaurants.

Secos aims to help as many girls as possible, but it isn't just about encouraging them to get off the streets. They are given support if they want to "exit their lifestyle", although this is now called "recovering", but the help Secos offers is as much to do with arranging drugs counselling programmes, sorting out housing issues and making sure the girls have regular sexual health checks. Violence against the girls is becoming more frequent, and Secos will pass information on dodgy punters onto the police, if the girls don't want to do it themselves.

"If they have certain problems, we will look at them and see if we can support them in any way," says Linda. "If we haven't seen that person before and it is a new face, we will go along and introduce ourselves. Initially, we just want them to use the service.

"A lot of the girls are very suspicious because the only experiences they have had with professionals have been very negative, maybe if they h ave been in care or have been in trouble. We have got to cut through that. It is a very slow process but hopefully as time goes on they get to trust us."

As we drive around an industrial estate, we see a girl, probably in her late teens, wearing a long sheepskin coat and knee high white boats. I find myself wondering if she looks like a working girl, before pulling myself up sharply. After all, is there such a thing as a working girl look?

As well as breaking down those barriers with the girls, Secos also has to overcome the preconceptions of professionals in other agencies, from housing authorities to police, to help them gain an understanding of the girls' lifestyles. It is only if all these agencies work together that the prostitution 'problem' can be properly addressed. "These girls are working to pay for a drug habit, therefore get them on a drug programme and you will solve the problem," Linda says. "But it is not as easy as that. It is looking at what caused the drug problem in the first place.

"Barnardo's approach is all about giving people hope for the future, but can you live in hope when you are in sub-standard accommodation and you've got social services on your back."

It's a quiet night tonight and there are few girls on the streets. I presume it's the cold, but Linda tells me they're often out in all weathers - drug habits don't disappear when the weather turns bad. As we drive towards where the van is parked, over the border, we pass a girl wearing a fur coat and short skirt.

Linda beckons her over, and asks if she's been to the van tonight. When she says yes, Linda asks if she's all right for condoms. It turns out she is, and she then continues back to her post and we drive on to meet the van.

Back in the van, Kelly is telling me that this is her last night on the streets. That tomorrow she's giving up heroin, doing another rattle, but this time it's for good.

"Every other rattle I've done has been for other people. I have got to do it for myself," she says. For herself, and for her son. He's well looked after by her family when Kelly's working, but she knows she isn't giving him the attention he deserves. Tonight, she insists again, is her last night.

"I'm only down here because I owe money tonight. After tonight I'm staying away. I want to be back into my career again, I want to be a mother again and just have my own house and get up and do my own things. That is my aim. I've got to have a goal to aim for."

I look out for Kelly when I return a week later, this time to try and persuade some of the girls to pose for photographs. She isn't there. I don't know if she's been back since and I'm reluctant to ring the Secos workers to check. On the whole, I think I'd rather keep that hope alive.