The pupils are confined to the rooms during school hours for up to three days and are only allowed out for toilet breaks. Meals are delivered to the room.

The move is part of a new approach called “assertive discipline”, which has been pioneered by Sir Dexter Hutt. He has introduced the isolation rooms into three schools in Birmingham where he is executive headmaster. “For some students, social interaction is more important than work,” he said. “If they are socially isolated, they miss that outlet.”

Pupils are put in isolation after receiving four warnings about their behaviour. Isolation rooms typically hold six pupils sitting in cubicles with partitions, meaning they cannot see or speak to their neighbour. Once in a cubicle, they have to study from worksheets.

However, teachers at one of the schools, the International, have complained that such methods are draconian; a modern version of the prison cooler.

There, teachers claim some pupils have sought time in the cooler as a badge of honour. A representative of the National Union of Teachers said: “With a lot of students it escalates the problem. All the other wannabe bad boys and girls want to follow them.”

Hutt rejected the criticisms. His success at improving results at another Birmingham school, Ninestyles, brought national attention and a knighthood.

When Hutt took over at the school in 1988 only 6% of pupils left with five or more GCSEs. Last year 72% left with five or more A-C grade GCSEs. As a result, Birmingham city council asked him to also take on the International and Waverley schools.

He insisted his methods had worked at the International. “Two years ago the behaviour was appalling. Pupils regularly threatened teachers. In one incident a teacher narrowly escaped having her hair set on fire,” he said.

“You can’t keep teachers unless you create a climate where children are able to learn. In some schools a small group of students ruin the atmosphere for the majority.

“A student who misbehaves gets two verbal warnings, then detention for one hour and finally a day in the isolation unit.

“It is very rare that a student gets sent there for three days. They either change their behaviour or we have to discuss their future with their parents.”

Ruth Robinson, head of the International school, said children had also been banned from wearing hats and hooded tops — or “hoodies” — inside the building.

Last week the Bluewater shopping centre in Kent banned youths wearing hoodies from the premises as part of a “zero tolerance” approach to antisocial behaviour.

Blair later backed the Bluewater policy when saying he wanted to make the restoration of “respect” for others a central plank of his third administration.

Hazel Blears, the minister for antisocial behaviour, says teenage offenders should be forced to wear US-style distinctive uniforms while carrying out community punishment. The uniforms would identify offenders and reassure the public, she says.

“People feel very strongly that they don’t often see justice being done,” she tells today’s Observer. “I want them to be identified.”

The government is also planning residential parenting courses for dysfunctional families and cheap leisure activities to occupy teenagers.

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