A review by the Alliance for Youth Justice, Article 39, Centre for Crime and Justice Studies, Child Rights International Network, Howard League for Penal Reform, INQUEST, Just for Kids Law and the National Association for Youth Justice has concluded that reform attempts “have ultimately failed, and continue to fail”.

The 40-page report analyses efforts to reform child prisons since 1998 and how they have measured up against successive government assurances that children will be kept safe, will not be subject to solitary confinement, will receive at least 30 hours of education per week, and will only be restrained as a last resort.

It makes five recommendations, chief among them the removal of children from the prison estate and the closure of child prisons, as well as the launch of a wide-ranging independent review of the circumstances in which children may be deprived of their liberty as a genuine measure of last resort.

Carolyne Willow, Article 39’s founder director and one of four contributors to the review, said: “With this review, which started before recent ministerial appointments, we have succinctly shared the evidence of past reforms, many of them deemed urgent, so that government has the best chance of introducing and implementing policy that will work.

“The cumulative evidence that imprisonment causes children serious harm, and cannot be made safe, is incontestable.

“We don’t want to be still documenting and writing about children suffering serious abuse and neglect in child prisons in 10 or 20 years. Ministers can and must change this never-ending cycle of child harm once and for all.”

Dr Laura Janes, a solicitor working with children and vulnerable adults in prisons, and a contributor to the review, said: “After working with children in prison for almost 20 years, one throwaway comment from a child client, who said ‘everybody knows you stay the age you come in at’, sticks with me.

“The act of imprisoning a child is to freeze their development, with terrible consequences for their health and their future. The use of prisons for children must end.”