One day after Connecticut announced it would become the first US state to sue the White House over the legislation, education secretary Margaret Spellings outlined new concessions allowing more schools to escape sanctions for missing yearly test targets and opened the door to further accommodations if officials are satisfied schools have rigorous accountability systems.
The waivers granted to special-needs students triple to 3 per cent the overall number of students schools may excuse from No Child Left Behind's testing requirements. Previously, exemption was confined to those displaying "significant" cognitive impairment.
Ms Spellings convened a panel to examine what many see as a flaw in the legislation whereby schools are measured on the test performance of a different crop of students each year rather than the progress of individual pupils over time.
But the concessions failed to appease Connecticut attorney general Richard Blumenthal. "Our determination to sue continues," he said. Earlier last week, Mr Blumenthal served notice that Connecticut would take the US government to court for imposing intensive new testing demands without requisite funding.
The lawsuit from Connecticut, home to some of America's academically strongest schools, is widely tipped to spur other states to take legal action too. Last week, officials in Maine were already contemplating following suit.