The nation's largest teachers union has donated more than $1.5 million to try to persuade Utah voters to kill the country's broadest private school voucher program.

In November, voters will decide whether to scrap a program created by conservative state lawmakers that would give parents $500 to $3,000 per child to spend on private school tuition, depending on income. Even affluent families with students in high-performing schools would qualify.

Utah has become the center of a national debate on spending public money on private schools. Groups on both sides of the issue are spending millions of dollars, anticipating that if vouchers are approved in Utah they will quickly spread to other states.

Radio and television commercials advocating one point of view or the other already are airing throughout the state.

Utah was one of 10 states targeted in the 2003-04 election cycle to adopt a voucher program by a political action committee called All Children Matter that is based in Alexandria, Va. The committee's headquarters are in Grand Rapids, Mich.

Teachers unions in Colorado, Ohio, Maine and Wyoming have also contributed several thousand dollars to fight vouchers in Utah, in addition to the $1.5 million contributed by the National Education Association, according to campaign finance reports due Monday.

In other filings, All Children Matter has been the largest supporter of Utah's primary pro-voucher group, Parents for Choice in Education, although it didn't donate any money in support of vouchers by Monday's filing deadline. All Children Matter is largely financed by heirs to the Wal-Mart fortune and the founders of Amway, according to finance reports in Virginia.

Lisa Johnson, a parent of three children and spokeswoman for anti-voucher group Utahns for Public Schools, said spending public money on private schools is the wrong thing to do when Utah has the nation's largest class sizes and spends less money per student than any other state.

"We've been told for many years that we'd like to do more for public schools, but it's too expensive," she said. "We think it's a little ironic that suddenly they found the $430 million to pay for private school subsidies."

Lawmakers set aside $9.3 million for the first year of vouchers, including $3.9 million to help public schools that lose students. Because only students who are new to the private school system qualify for the vouchers, the program is expected to cost several hundred million dollars within a decade.

Voucher proponents say public schools don't work for all students and that parents should be able to use a portion of the money spent on students in public schools on a voucher if they want to.

Messages left with Parents for Choice in Education and the National Education Association were not immediately returned Monday.