The deputy head was 10 minutes late to meet 13-year-old Lara on her first day at school.

Alan Mitchell was not held up in a meeting, as he told his new pupil. He was deliberately testing her, to see if she would still be there when he returned.

“I set her a test at lunchbreak,” he said. “I wanted to know what makes her tick and how much she wants to be here.”

This was one of several techniques that Mr Mitchell, deputy at St John the Baptist Catholic comprehensive in Woking, used to assess the three excluded pupils admitted to his school this year.

This month, Charles Clarke, the Education Secretary, announced that he wanted all heads to accept a number of excluded pupils each year, rather than allowing them to be consigned to underperforming comprehensives.

Tim Collins, shadow education secretary, attacked this plan, claiming that it would guarantee “a yob in every playground and a thug in every classroom”.

But in Tory-controlled Surrey, such a scheme has been operating for three years, with excluded pupils allocated to schools according to a points system. Each secondary starts with 1,000 points, to which extra points are added for statemented pupils and those on free school meals. Each time a school excludes a pupil, it gains 25 points, and when it takes in an excluded pupil, it loses 25 points. Whenever the authority is trying to place an excluded child, it approaches first those schools with the most points.

Chris Grayling, Conservative MP for Epsom and Ewell, does not back the county’s scheme. He said: “It’s no solution to put unruly pupils back in the classroom “You need to take them out of the classroom, sort them out and help them to address their issues. If someone is a continuous disruptive element, you can’t condemn the rest of the class to having their education ruined.”

Only 20 per cent of pupils have had to be excluded from the school to which they were transferred in the three years that the project has been running.

And Sharon Ghiacy, Surrey social inclusion officer, said that there are now fewer “thugs” in the authority’s schools. “For many pupils, it’s a fresh start,” she said. “It’s a shock to be excluded. So this is a chance to make the right life choices.”

John Cain, head of Reigate comprehensive, admits that some altruism is involved. He said: “Obviously it contains tensions and there’s the concern that it will affect results. But we know that every school in Surrey is playing the game and children deserve all the support they can get.”

Mr Mitchell agrees: “The scheme works because we don’t have heads with tunnel vision, saying, my school, my school, my school. We see our responsibility as taking care of all children in Surrey. It would be very easy to say ‘no’ to these pupils. But if you’ve committed a crime and made recompense, you should be able to start with a clean slate.”