RALEIGH, N.C. — North Carolina's Supreme Court is considering a case that could decide whether a pre-kindergarten academic program designed to boost the educational prospects of poor children must be expanded to enroll every needy 4-year-old, a move one estimate put at up to $300 million a year.

The state's high court will hear from attorneys Tuesday in the latest chapter in a 19-year-old dispute brought by poor school districts in Hoke, Halifax, Robeson, Cumberland and Vance counties.

The first of two related lawsuits, named for the Leandro family that brought them, led the North Carolina Supreme Court to rule in 1997 that every child has a constitutional right to an education that allows them to compete for a job or higher education and to be a functional citizen. The court ruled in 2004 that the constitutional right to a sound, basic education includes helping children who are at risk of falling behind their peers with pre-kindergarten services.

A three-judge panel of the state Court of Appeals last year unanimously backed Superior Court Judge Howard Manning Jr., who ruled in 2011 that legislative cutbacks to the state's More at Four program would deprive most disadvantaged 4-year-olds from benefiting.

Manning, selected by the Supreme Court to oversee compliance with its earlier school-funding decisions, said the Republican-led Legislature effectively limited the 8-year-old program renamed North Carolina Pre-Kindergarten by restricting the number of slots for at-risk 4-year-olds due to chronic health problems, or because their families were in financial hardship or did not speak English at home.

"This court's 2004 decision in Leandro II is not an advisory opinion, and the state cannot simply ignore it," Melanie Black Dubis, an attorney for the poor school districts, wrote in court filings. Manning's "order, its affirmation by the Court of Appeals, and this appeal concern the state's failure to provide the constitutionally-required remedy, not whether a remedy is required."

NC Pre-K enrolled about 25,000 children in 2012, down from about 35,000 in 2010 after lawmakers cut its funding by 20 percent and imposed other restrictions. A September 2012 survey found that nearly 12,000 children were waiting for Pre-K services. Spokesmen for the state Health and Human Services Department, which now runs the program, did not respond when asked for current enrollment figures.

Expanding the program to all 67,000 children who may be eligible could cost taxpayers up to $300 million a year, former Gov. Beverly Perdue's administration estimated last year.

The case pits the Legislature's changes against poor and urban school boards, the State Board of Education, the North Carolina School Boards Association, disability and children's rights groups, the state's leading teachers' association, and former Gov. Mike Easley. Easley started the program and laid out his opposition to the legislative changes in a court filing.

Lawyers working for Attorney General Roy Cooper, a Democrat responsible for representing the GOP-led General Assembly, argued in court filings that Manning has no authority to require a statewide expansion of pre-kindergarten services. That's not what Manning ordered, instead directing that state officials could not create barriers that would deny an eligible child admission where a program exists, the appeals court said.

While Gov. Mike Easley, the state school board, and other officials promised in 2004 to expand services to at least 40,000 at-risk four-year-olds at an annual cost of $160 million, that was a goal and not "an enforceable obligation to expand and maintain a state-wide pre-kindergarten program in perpetuity," wrote John Maddrey, Cooper's top appeals lawyer.

The change from More at Four to the NC Pre-K Program barely changed its quality or effectiveness, but shrank the access during the 2011-12 school year, according to a report this year by the Frank Porter Graham Child Development Institute at the University of North Carolina at Chapel Hill. Previous studies by the institute validated the program's effectiveness.

Duke University researchers reported last year a "moderately large" improvement in third-grade test scores for children enrolled in Smart Start, a state program aimed at improving childcare for children up to age 5, and pre-school for at-risk children previously named More at Four, when those programs got adequate state funding. The study looked at 650,000 third-graders and compared effects in places and years when the programs were well or poorly funded.