Who could object to seeing a disadvantaged child plucked from a harmful background and set down into calm classrooms and green playing fields? No one. But as the idea of placing vulnerable children in boarding schools gains currency, and the Government negotiates with local authorities about testing the idea, voices are warning that this will only ever suit a relatively small and carefully selected group of young people.

Among those involved in hammering out the details of how such a scheme could work, there is much private anger at what are seen as the inflated public claims for it made by Sir Cyril Taylor, chairman of the Specialist Schools and Academies Trust.

Sir Cyril rightly says that boarding school places would be far less expensive than either foster care or residential homes for the 61,000 children in care in England, and that extra boarding capacity can created at new academies.

But both those who understand the boarding ethos, and those working with vulnerable children, say that such placements should only ever be done child by child.

“We took a poll of about 20 care leavers and they thought it was a great idea, but only if it was something a child wanted and children were at the heart of the decision,” says Maxine Wrigley, the national co-ordinator for A National Voice, an organisation run for, and by, young people in care.

“They had questions about what would happen in the holidays, when everyone else is going home to fairly wealthy families, and also whether there would be any dedicated support in the boarding houses. After all, we’re talking about a different kind of child here. But if it was the right place, they thought that in terms of educational outcomes it could be fantastic.”

In fact, boarding schools have a long track record of doing well by a smattering of disadvantaged children. John Walker, chair of the Incorporated Association of Preparatory Schools’ boarding committee, and head of Abberley Hall school, in Worcester, says: “People would be surprised how many children going through boarding schools are helped in some way.

“I know of a considerable number of children in boarding preparatory schools who would definitely be in care if they weren’t there. Boarding schools offer a high quality academic environment, and give children the opportunity to be in a very safe environment with their peers.

“They are very good at building up confidence. A lot of behavioural problems come from lack of confidence.”

However, he acknowledges that entrenched difficulties would be hard for a school to handle. “We are here to help where we can, but we cannot do everything. There is always the fear with these grand ideas that they won’t be properly funded or thought through.”

David James, head of English at Haileybury, where fees are pound;22,000 a year, foresees a division among independent schools about who would take part. “Will Harrow, Eton and Rugby open their doors to these children, or will this only be something for schools which are struggling to fill their beds, and which have problems of their own?”

As a housemaster, at the sharp end of daily boarding school life, he has other concerns, too. How will children be selected? Will places be properly funded, to include music lessons and school trips? And how well will vulnerable young people survive?

“The children I deal with can be very materialistic. They want to know what your parents do, how many houses you have or where you go on holiday. It sounds, in theory, like a good idea, but our staff haven’t been trained to deal with children with particular behavioural problems.”

However, he says, a regime that keeps children busy from nine in the morning to nine at night could do wonders for some. “I know that staff would relish the opportunity to help them make a fresh start if the circumstances were right,” he says.

The Government is currently hoping to place at-risk children from a handful of local authorities in boarding schools in order to test the idea. Andrew Adonis, education minister, went from a London council flat to boarding school courtesy of charitable funding. This is not a new idea, as after the Second World War, plenty of children - often those of military personnel - were paid for by the Government to go to state boarding schools. But boarding fell out of favour and boarding houses started to close.

Now, for the first time in years, the Government is investing in 35 schools in the state boarding sector to expand capacity. Four schools have recently been given funding to refurbish or build additional places.

Melvyn Roffe, chair of the State Boarding Schools’ Association, says:

“State boarding schools have decades of experience working with children to provide a situation where vulnerable and non-vulnerable children work together.

“We could see a situation where we took up to 15 per cent of such children, with some additional capacity, provided it was sustainable. But schools aren’t an adjunct of the criminal justice system. We must be able to decide whether a child is suitable for boarding.”

There are other barriers, too. Melvyn Roffe says that if a local authority places a child at boarding school outside its area, it counts as the same, in its records, as having failed to find that child a foster home.

And, as Colin Morrison, chair of the Royal Wanstead Children’s Foundation, says, local authorities seem prejudiced against boarding schools. “The Department for Education and Skills had a conference with 130 people on this, but only three or four local authorities were represented. We ended up talking to ourselves.”

Prejudice against the new kinds of boarding could be countered by the ideas currently being explored by the Specialist Schools and Academies Trust.

Kingswood city technology college, in Birmingham, is planning 100 boarding places, 20 of which would be set aside for children in care. Melvyn Roffe has doubts it would work.

“I could see a smallish academy with a kind of hostel arrangement for children temporarily unable to be at home, but the idea of barrack-like blocks of children attached to schools, which by definition are coming out of difficult circumstances, is only going to get in the way of the good stuff that could be happening in this area. The real question is, how are you going to revive boarding in state schools?”