Vulnerable children desperately in need of stable, loving homes are finding themselves shunted from one set of foster parents to the next.
Debbie is, in many ways, a typical 11-year-old. Slim, with shoulder- length dark hair, she's lively, assertive and demanding. She loves music - she tinkers on the keyboards, though she has passed no exams -and there is little she likes better than to dance, particularly to the Spice Girls. And when she's on her own, she'll be busy playing with her Nintendo machine. But her tale differs from the average girl of her age because she can't even remember how many homes she has had in the past few years, since she was taken into care when she was aged five. Her mother is dead and her father's whereabouts are unknown.

This is not a tale about the horrors of children's homes. Debbie lives in a residential unit which she likes and where she wants to stay. Her story is about being let down by those who are supposed to offer an oasis of stability in the state child care system - foster parents. For five years she was repeatedly moved between foster homes, a bewildering experience which has destroyed any faith she had in finding a stable family which might have supported her through her teenage years.

As Debbie speaks, she racks her memory to recall the sequence of families. It started with being placed in emergency foster care. "They were really kind and friendly." But after a few days she had to move on. Then there was the family with two children, both older than her, one of them disabled, the other at college. "We just kept on arguing and it didn't work out," recalls Debbie. She remembers that one day there was a meeting at the house of case workers and family. "They all decided that I should go." But not before she joined the family on their holiday to Tunisia. "It was the best holiday I've had - the swimming pool and the food. I felt upset afterwards that they had spent so much on me, and I had to go. I packed my stuff a few days after we got back and moved onto another family."

At this point, her memory starts to falter - one foster home melts into another in her story. There was the mother and her 13-year-old daughter she stayed with when she was 10. "The lady was really nice, but the girl and I kept arguing. She kept hiding all my Barbie dolls which was really annoying." Debbie lasted there for two or three months.

And so the tale goes on until last year, when she went to a council residential unit, home to seven young people, but not designed as a permanent home (Debbie has already been there longer than normal). "I don't want to go back to foster care any more," she says. "I get hurt and upset by people saying that they don't want me to stay."

Debbie's experience is not unusual. Nor is she an impossible child. Challenging, but not violent or destructive - certainly manageable in the hands of a well-trained, expert parents. The way she has been let down points to a serious flaw in the social services system, which increasingly places children in foster care, rather than institutional homes. The cuddly image of indulgent, endlessly patient foster parents, guardian angels rescuing the most difficult young people from institutional hell is fading fast. A lot, for all their best intentions, are not well enough prepared or trained to cope with the needs of difficult children.

Children are often poorly matched with families drawn from too small a pool and are frequently placed hurriedly before professionals have had a good chance to tackle some of the problems that brought them into care in the first place. Now that some local authorities have closed most or all of their children's homes, social workers have little choice but to place children with what may be the only available foster family. The result is predictable - frequent breakdown that does untold harm to an already vulnerable and damaged child.

Last month, government inspectors reported that in their study one in eight children had been moved three or more times. Most children were given no choice of foster home. Brothers and sisters had sometimes been separated. Kenneth Redgrave, a consultant in child care based in Northwich, Cheshire, deals with many of those who are damaged by such experience: "I meet children of 10 years old who have in fact had 10 foster homes since the age of five. My record is a 14-year-old with over 20 moves. Many such children can attach to no one. They run off and 'get lost'.

"When a child comes into care, sometimes you are lucky if there are three vacancies with foster parents. None are ideally suited but the social workers may have little choice but to place the child there. Then the child proves disruptive, doesn't fit in and so the foster parents say it has to be moved. As soon as that happens you have started to damage the child, who may have already experienced abuse or rejection. Next time, it will become that bit more difficult for them to attach to the new family."

The profession seems at last to be acknowledging the scale of the problem: the shift in favour of foster care means that 33,000 children are accommodated in England and Wales in such homes, out of the total 49,000 in council care. If even a small proportion of these children are going through what Debbie has experienced, then social services departments have been quietly watching a major scandal unfolding.

The future of foster care will be raised by Sir William Utting's current inquiry for the Government, which is focusing mainly on children's homes. And a report from the Association of Directors of Social Services has recently urged councils to take a long, hard look at the quality of their foster care. Bill Bulpin, who chaired the ADSS inquiry, believes that councils should consider better training for foster carers. Currently they are vetted during a series of evening and weekend sessions that include some training, but there are few in-service courses. The tradition of volunteer parents accepting children should continue, says Mr Bulpin, but those dealing with the most difficult children need professional expertise.

The National Foster Care Association believes that raising the levels of financial support would help, particularly in expanding the pool of would-be parents. At present rates vary from pounds 78 a week for a teenager in some rural areas to pounds 185 a week in parts of inner London. For a toddler, the rates vary between about pounds 44 a week and pounds 125. An additional sum, equivalent to the weekly grant, is usually also available for holidays, birthdays and Christmas.

The NFCA is critical of council's efforts to recruit new foster carers. "They do not have enough people who can cope with those who have been physically or sexually abused or are disabled." There is, in short, consensus that something must be done. But there was just such a consensus about children's homes a decade ago. Inaction then has led to further scandals and another lost generation of children. The big question now is whether the services will improve quickly or once again fail children such as Debbien