UP to 3.5 million US students will be free to leave more than 8,600 flagging state schools this September under President George Bush's school choice plan, the White House said last week.
Headteachers at the schools - identified by state education chiefs as falling short of academic yardsticks for the past two years - must inform parents that they can transfer their children to better local schools. The controversial sanction also orders schools to pay pupils' travel costs to attend alternative schools. Where they have under-performed for more than two years, schools must offer students catch-up lessons from external education providers.
The number of schools affected - 9 per cent of the US total - far outstripped the 3,000 to 5,000 Congress had been led to expect.
"For the first time, school districts must tell, and parents will know, which schools are not making sufficient academic progress," declared US secretary of education, Rod Paige.
But education officials said extra transport and tuition expenses would hamper the education Bill's goal of bringing all US schools up to scratch by 2013.
"Moving children from one needy school to another may not be the solution - we need to ensure every school gets adequate funding," said California's state superintendent of public institutions, Delaine Eastin.
An education department spokesman said "unprecedented levels of funding are available to cover costs". The government has earmarked $13.2 billion (pound;8.5bn) for school improvement for 2003.
Clive Belfield, research director of Columbia University's Teachers College, said the measures permit poor pupils to escape "dangerous dystopias" that initiatives have failed to reform.
Comparing it to so-called name-and-shame policies in Britain, Mr Belfield, also a research fellow at Birmingham University, said the US scheme involved less inspection and produced a considerably longer list of schools deemed inadequate. The standards are set by the states themselves and are largely test-based.
Race also looms large in the US debate, Mr Belfield noted. "The test-score gap between African-American and white students is equivalent to one year's schooling."
Disparities in the numbers of below-par schools reported by individual states highlight varying standards across the US. Michigan identified more than 1,500 laggards, or 40 per cent of its schools, but Arkansas and Wyoming highlighted none. In the more populous states, more than 1,000 schools fell short of California's standards, while Texas failed just 121.
A state official said Michigan's high number reflects the rigour of its academic requirements. "I don't think Michigan should be penalised because it's ahead of the curve in holding schools to higher standards," he said.