PARENTS' right to choose should be curbed to rescue sink schools, according to the Government's leading adviser on transient pupils.
Dr Janet Dobson told a Birmingham conference that "mobile" children - including refugees, and those in council care - should be shared more evenly between schools.
"It's madness to herd all these children together in one set of schools and leave the high-achievers in another set," she told the conference organised by the city's education authority and its headteachers.
Dr Dobson, who leads the field on research into pupil mobility and is preparing a report for the Government, said: "We have to shift our whole perception of schools as communities. Mobility does matter in relation to achievement, especially in relation to the least-advantaged."
Research published in last week's TES suggested that Hackney's shifting school population has cost the east London borough 34 places in the league table of primary school results. Transience is strongly linked to poverty.
Dr Dobson said ministers should consider "a strategy to spread the mobility evenly around schools. We must grasp that nettle," she said. "Unless we do, we will not have the equality we wish to see."
Speaking at the same conference, education minster Estelle Morris announced that schoolchildren in England will be issued with identity numbers next September to help deal with the growing crisis of pupil mobility.
"Unique pupil identifiers" are already being tested in Birmingham, Durham, Lewisham in south London, Staffordshire and Suffolk. The Department for Education and Employment says it aims to go national this year.
Children will be registered by their local authority at the start of their school career and their numbers will stay with them until they leave education. The Government hopes this will help track the extent of the movement as well as providing statistical data on their progress. In Birmingham alone, one in five pupils changes schools each year at "abnormal" ages of transfer.
Ms Morris admitted that the Government had "no solutions as yet" to the problem. But she stressed that the DFEE was not solely to blame. Social security and housing ministers also had to address the problem.
Traditionally, children of people in the services, travellers, refugees and asylum seekers have been seen as the main source of pupil mobility. But the conference was told that debt, harassment and broken families all forced the movement of many children.
Ms Morris said: "All the evidence shows that pupils who are highly mobile are more likely to truant and more likely to be excluded. Many children who have special education needs are those who have been mobile during the academic year".