Proponents call it a tool to reduce class sizes in public schools.

Opponents see it as a weapon aimed at eroding the public-school system to the benefit of private schools.Both sides watched it pass from the Senate to the House Friday.

SB155, sponsored by Sen. Howard Stephenson, R-Draper, provides an income-tax credit to certain parents who place their children in private schools.

The bill passed the Senate on a 17-10 vote and will be considered, along with a mountain of other bills, by the House during the last three days of the session.

The bill gives local school boards the option of giving out "certificates of participation" to families who request one for a child placed in private schools. The certificates, required for the tax break, may only be awarded by districts for the purpose of managing growth or reducing class sizes.

As Stephenson sees it, fast-growing districts could use certificates of participation to help ease the burden on specific schools while a new school is being built. Then after the new building is open, the district could stop issuing the tax-credit certificates, he said.

"This is a growth-management tool. A tool school districts can use to control classroom size," Stephenson said. "It's voluntary on everybody's part."

But opponents of the bill, most notably two Senate Democrats with backgrounds in education, said it forms a scenario in which taxpayers are in effect supporting private schools.

Sen. Joe Hull, D-Hooper, who is an educator, said the bill could "help destroy the funding of public education" and create "a bigger chasm between the ability to learn in public education and the elite private schools."

"We need to provide the best education to the populace possible - equal to the poor and to the rich," said Hull, who said Thomas Jefferson would have voted against the bill, too. "We all need free and equal access to public education."

Sen. Millie Peterson, D-West Valley City, said she is concerned about taking any money away from public schools.

"As long as we cannot afford a textbook for every student, can we really afford to give away money to private education? I don't think we can," she said during the second and final debate of the bill in the Senate.

Stephenson sponsored essentially the same bill a year ago and it passed the Senate on a 16-12 vote. It was then amended in the House to set up a one-year demonstration project in one school district. The amended bill was rejected by the House on a 26-46 vote.

Under the proposed law, the tax credit could be as high as about $1,900 per child. It would not apply to students who are taught by their parents at home.

Stephenson said that for any student receiving a certificate of participation, the school district would retain approximately $1,900, or the value of the weighted pupil unit used by the state Office of Education, and an equal amount would be forwarded on to the private school.

The State Tax Commission estimates a cost of $50,000 to implement the law. It would not take effect until fiscal 2000.