Leading the fight is the National Education Association, a union of 2.7 million members and a political adversary of the administration. The union mobilized its forces for John F. Kerry in the 2004 presidential race, and its objections to Bush's education law prompted Rod Paige, the former secretary of education, to call the NEA a ''terrorist organization."
The other plaintiffs are nine school districts -- in Michigan, Vermont, and Bush's home state of Texas -- as well as 10 NEA chapters in those states and New Hampshire, Connecticut, Illinois, Indiana, Ohio, Pennsylvania, and Utah. The NEA is financing the lawsuit.
No Child Left Behind faces battles on other fronts, too. The Republican-led Utah Legislature voted Tuesday to put its educational goals ahead of the federal law despite the possible loss of $76 million; Connecticut is planning its own lawsuit; and other states are balking over money.
The law is widely considered the most significant federal education act in decades. It puts particular emphasis on ensuring that schools give attention to minorities and poor children, who have long fallen behind on achievement.
Dennis Pollard, a lawyer representing schools in Pontiac, Mich., said the lawsuit is strictly about funding. ''There is no intent to frustrate the purpose of No Child Left Behind," he said.
The lawsuit is built upon one paragraph in the law that says no state or school district can be forced to spend its money on expenses that the federal government has not covered.
''What it means is just what it says -- that you don't have to do anything this law requires unless you receive federal funds to do it," said Robert Chanin, NEA general counsel.
''We want the Department of Education to simply do what Congress told it to do. There's a promise in that law, it's unambiguous, and it's not being complied with."
The lawsuit accuses the government of shortchanging schools by at least $27 billion, the difference between the amount Congress authorized and what it has spent.
Education Secretary Margaret Spellings, as chief enforcer of the law, is the defendant. She is accused of violating the law and the spending clause of the US Constitution.
