The attack was made after the third reading of the Children and Young Persons Bill in Parliament on Wednesday.

"It is sad that such a good Bill should have missed such a good opportunity to protect some very vulnerable children," said Tim Loughton, the Conservatives' minister for children.

"More than 70 per cent of children in custody have been in care; the government is failing to tend adequately to their needs. If we want to reduce our alarmingly high recidivism rates and improve the life chances of these young people, we have to make sure they get the care they require."              

Some 10,000 children pass through the secure estate for juveniles per year. At any one time there are approximately 3,000 children under the age of 18 held in custody.

According to the Youth Justice Board, 71 per cent of children in custody have been in the care of, or involved with, social services prior to entering custody.