The Colorado Supreme Court ruled Monday that the state's school voucher program is unconstitutional because it strips local school boards of control over education.

Colorado's voucher law - the first in the nation since the U.S. Supreme Court said in 2002 that voucher programs are acceptable - was never put into effect because of legal challenges.

The high court's 4-3 decision upheld a lower court ruling.

The law would have offered vouchers of $4,500 a year to public school students to help cover their tuition at private or parochial schools. The program was supposed to start next fall.

But the high court said the program requires school districts to turn over a portion of locally raised funds to private schools, over which local school boards have no control. That violates the local-control provisions of the Colorado Constitution, the court said.

Voucher supporters are likely to introduce a new version in the 2005 Legislature to conform to the ruling.

"I think it would be fairly easy to draft legislation that didn't use local dollars," Rep. Nancy Spence said.

The court challenge was brought by teachers, education groups and religious organizations. They said the program could direct tax money to private schools motivated by religious ideology.

Ron Brady, president of the Colorado Education Association, the state's largest teachers' union, said it will likely be impossible to devise a voucher program that passes state constitutional muster because of strong prohibitions against giving taxpayer money to private or religious institutions.

Voucher programs have withstood legal challenges in Cleveland and Milwaukee. Washington, D.C., is scheduled to begin using vouchers this fall, and Florida's program is operating while a state appeals court considers a challenge.