PHOENIX — A proposal to sharply expand the use of tax dollars to send students to private and parochial schools suffered a severe, and perhaps fatal, setback Thursday.

The House voted 31-27 to kill a proposal to make vouchers available to any student living an area where the average income is less than about $44,000 a year. Backers argued the move would provide parents of needy children with additional educational opportunities.

But Rep. Ethan Orr, R-Tucson, one of the foes, said talk of diverting more state tax dollars to send kids to private schools is premature.

“Parental choice starts with well-funded and well functioning public schools,” Orr said, arguing the voucher discussion can occur “once we fix our funding formulas, once we make our public school system one of the best in the nation.”

Proponents can ask the measure be reconsidered next week. But it remains unclear whether Rep. Debbie Lesko, R-Peoria, sponsor of HB 2291, can find the votes to reverse the decision.

Lawmakers approved the original program in 2011 to provide an alternative to public schools for students with disabilities and foster children. It was expanded to also include any student attending a school rated D or F.

In addition to paying tuition and fees at private and parochial schools, the vouchers can become an account parents who home-school their children can use to purchase online services and supplies.

The number of students actually now eligible is in dispute, with figures ranging from 60,000 to 150,000.

Lesko’s measure would make the vouchers, generally worth $5,400, available to any youngster whose home is in a zip code where the average household income is less than 185 percent of the federal poverty level for a family of four.

While Lesko estimated that would make an additional 112,000 students eligible, she said there is a cap in existing law that limits new vouchers to only about 5,400 students a year.

Rep. Bruce Wheeler, D-Tucson, countered the cap could be repealed any time, and it automatically expires after 2019.

Wheeler also objected to the fact nothing in the law requires students who get the vouchers to pass the same standardized tests as those in public schools.

Rep. Justin Olson, R-Mesa, said Wheeler’s comments are based on the premise that parents cannot be trusted to make the best educational choices for their children.

“That is an arrogant point of view to think that I know better for your kid than you know for your own kid,” he said.

But Rep. Heather Carter, R-Cave Creek, said that shows “a fundamental misunderstanding of what school choice is.” And Carter said the push for an expanded voucher program ignores all the choices parents already have.

She said Arizona is an “open enrollment” state, meaning students can attend any public school anywhere they want as long as there is space.

Carter also pointed out Arizona has one of the most extensive charter school networks anywhere in the country. These schools, which can be run by private entities, are considered public schools and subject to some — but not all — of the same regulations as traditional school.

They also must accept all applicants if there is space, cannot pick and choose students and cannot charge tuition above the state aid.

“That is what school choice is about,” she said. “That is what parental choice is all about.”

By contrast, she said, the concept of vouchers, which originally was meant solely for some children with special needs, has now become “a debit card” for many more parents to use.

“So what’s happening now is we are driving taxpayer dollars into a system of private schools,” she said.

Carter said the state already has set up a system of scholarships, funded by tax credits, for needy parents and others who want to send their children to private and parochial schools

Lesko argued the vouchers actually save money for taxpayers. She said the typical cost for a student in public schools is about $8,800 a year.

But that includes locally raised dollars. Legislative budget analysts have said as far as the state treasury is concerned, the vouchers actually cost more than what the state pays in aid for students to attend traditional public schools.

The idea parents know what’s best educationally for their youngsters was disputed by Rep. Lisa Otondo, D-Yuma, a former middle school teacher.

She said many of the parents who came in to ask about their children were unable to help them with their math and language homework. And Otondo questioned whether they would know if their youngsters are doing better in a private school, or even learning what they need by being taught at home.