PHOENIX — Education groups are making a last-ditch effort to halt what is now a limited school voucher program before it spreads.

Attorney Don Peters asked the Arizona Supreme Court on Friday to conclude the current program, labeled Empowerment Scholarship Accounts by lawmakers, amounts to unconstitutional aid to private and parochial schools. He said it makes no difference that parents choose where to use the funds.

Peters, whose clients include the Arizona Education Association and the Arizona School Boards Association, also said the ability of parents to use the state dollars to send their children to parochial schools violates a separate constitutional ban on using public dollars for religious worship or instruction.

Challengers to the law, first approved in 2011, struck out earlier this month at the state Court of Appeals.

But Peters said he has reason to hope for a different result at the state’s high court: a prior ruling by the same court voiding a different version of the program.

In his legal filings Friday, Peters warned the judges their ruling affects more than just the students now eligible for the vouchers. That includes those with special needs and any youngster attending a school rated D or F by the state Board of Education.

He pointed out the Goldwater Institute, which has championed the vouchers and is defending the law, has said it is interested in creating a statewide program.

That would give every one of the 1.1 million students in public schools the chance to use tax dollars to attend private or parochial schools, and leave public schools with only the money appropriated for any students left in the system, while the Arizona Constitution requires the Legislature to maintain a “general and uniform” public school system.

“If public education could thus be completely transformed into a matter of decentralized, private choice, virtually all constitutional requirements for public education would be effectively nullified,” he wrote.

But Clint Bolick, an attorney for the Goldwater Institute, said those fears are unfounded.

“The constitutional requirement demands the Legislature provide public schools for all kids who want them,” he said, even if that turns out to be a minority of school-age children. “And that requirement is never going to go away.’’

And Bolick said the fact that funds wind up being used for students to attend private and parochial schools does not offend other constitutional provisions.

That law requires the state treasurer to set up a special account that parents could tap to pay tuition and fees for their children at private or parochial schools or for other educational instruction.

The aid is equal to 90 percent of what the state would otherwise pay in state aid to send that child to a public school, a figure that depends on everything from grade level to the child’s needs. Legislative staffers put the scholarships at anywhere from $1,700 to as high as $26,000 for those with special needs.

In upholding the law, the Court of Appeals said it doesn’t offend the constitutional ban on state aid to private and parochial schools just because the dollars ultimately wind up there. They said the parents are the true beneficiaries of the dollars, using them to decide where best to educate their children.

“It’s a false dichotomy,” Peters said, saying the schools are equal beneficiaries.

He said the earlier judicial finding — that parents making the decision to use the money at a church school does not amount to state funds being used for religious instruction — ignores the reality of what happens.

Bolick said the state Supreme Court even has upheld funds paid directly to religious institutions, like the Salvation Army, for services.

He said what also makes the legislation legal is that parents need not spend it on private or parochial schools. Instead, they can use it to get tutors or online education for their students who do not attend public schools, and even buy certain specific services directly from public schools.

But Peters said the record from the early stages of the program shows virtually all of the dollars did, in fact, go to tuition and fees at private and parochial schools.

The justices have not decided whether they will review the appellate court ruling.