A drive to cut the number of children behind bars in England and Wales – the highest in western Europe – has failed.
The Youth Justice Board (YJB) has missed its target to reduce by 10 per cent the number of youngsters in custody between 2005 and 2008, it will announce later this month.
The board had aimed to lower the juvenile prison population in England and Wales from 2,676 in March 2005 to 2,408 by last month, appealing to youth courts to use community sentences instead of custody.
Instead the board has presided over a rise of 8 per cent over the period, with the numbers of youngsters in custody reaching 2,883 by February.
The YJB says it can cope with the high numbers of juvenile inmates, but admits the total is expected to climb higher by the summer.
Penal reformers reacted angrily to the disclosure, and warned that imprisoning youngsters was counter-productive as three-quarters of them went on to reoffend.
Frances Crook, director of the Howard League for Penal Reform, accused the board of acting as an "extension of the prison service".
She said: "The YJB's turn-key mentality has overridden any attempt to grapple with youth crime issues beyond managing the movement of children within the juvenile estate. Hence they've not just failed to meet their targets, but actually seen things get worse."
Enver Solomon, deputy director of the Centre for Crime and Justice Studies at King's College, London, blamed the rise on the "criminalisation" of children by police who – under pressure to meet targets – handed out cautions and penalty notices to teenagers for relatively minor offences.
"This is a black mark against all the Government has achieved and the investment they have put into the youth justice system," he said. About twice as many children are jailed than in Germany, which has a bigger population, and four times as many as in France.
One reason is that the age of criminal responsibility is 10 in England and Wales, lower than anywhere else in western Europe, apart from Scotland, where it is eight.
Another is that the rapid rise in the number of anti-social behaviour orders being handed to children means there is greater risk they will get caught up in the criminal justice system.
More than 80 per cent of the youngsters given custodial sentences are sent to youth offender institutions, which are run by the prison services.
The rest are held in secure training centres, privately-run units aimed at rehabilitating vulnerable youngsters, or secure children's homes run by local authorities.
The United Nations condemned Britain's record on young offenders three years ago, but since then the situation has further deteriorated. Rod Morgan resigned as the YJB's chairman last year with a warning that youth custody services were on the brink of crisis and that targets for bringing offences to justice were having "perverse consequences".
A spokeswoman for the YJB said: "The law makes it clear that for young people under 18, custody must be the last resort, but sentencing decisions in individual cases are a matter for the courts.
"The Youth Justice Board believes there is scope for reducing the use of custody and is working with sentencers to achieve this."
She said the 10 per cent target had been an "aspiration" that underlined the board's commitment to reducing use of custody. But she said its success largely depended on a range of factors that were outside the YJB's control.