Medway Secure Training Centre (STC) in Kent will hold 40 of Britain's most dangerous young tearaways under controversial "secure training orders" brought in by the Conservatives.

The STCs, run by private companies, were opposed by Labour in opposition as "colleges of crime".

Home Secretary Jack Straw says the emphasis will be on rehabilitation

But shortly after taking office, Home Secretary Jack Straw announced he would go ahead with plans to build five of the centres.

He said it would be a waste of public money to cancel them.

But Mr Straw has promised to replace the "secure training orders" with "detention and training orders".

These will put the emphasis on rehabilitation and care, rather than punishment.

There will be higher than normal level of staff at the centres and most of them will have a childcare rather than a penal background.

Inmates at Medway, which is run by Group 4 security, will also have their own cooking and clothes-washing facilities to try to develop self-reliance.

'Retrograde step'

However, some children's and prison groups remain unconvinced.

Children's Society chief executive Ian Sparks said the estimated £5,000 weekly cost of housing each child would be better spent on providing more local authority secure accommodation.

"We are in danger of creating dumping grounds for the children society doesn't know what to do with," he said.

The National Association for the Care and Resettlement of Offenders said the new centres were a "retrograde step".

Prison and children's groups say it is a "retrograde step"

NACRO principal officer Paul Cavadino said: "Even institutions with constructive regimes have invariably produced high reconviction rates for juveniles, often increasing rather than reducing their chances of reoffending."

Mr Cavadino said disruptive child offenders should be dealt with near their homes in secure local authority units.

He went on: "Secure training centres are a very expensive option. When all five centres are open the cost will be over £30m a year.

"Spending the same amount on developing intensive supervision programmes in the community would be much more effective in cutting juvenile crime."

Conservative home affairs spokesman James Clappison said: "Labour's policy on the treatment of children and young people in custody constitutes a shameful and dramatic change of mind."

Former Home Secretary Michael Howard brought in the STCs in response to concern about serial young offenders who could not be jailed because of their age.

Before the Secure Training Orders were introduced, children under 15 could only be imprisoned for the most serious crimes like murder and manslaughter.