Two-thirds of a nearly $15 million federal grant awarded to Hawaii to fund public pre-kindergarten classrooms at charter schools has been slashed from spending bills in Congress — a move that officials warn would cut off preschool access for more than 700 isle children from low-income families.

Funds for the federal Preschool Development Grants, a program aimed at building and expanding high-quality preschool in more than 200 high-need communities across 18 states, have been eliminated from House and Senate spending bills.

The state’s Public Charter School Commission last year was awarded a four-year grant to establish 18 new pre-kindergarten classrooms, starting with four on Hawaii island this school year. Plans call for establishing preschool classes at two more Big Island schools next year, and five more there the following year, along with three on Oahu, two on Kauai and one each on Maui and Molokai. The award also comes with requirements to ensure quality, including low student-teacher ratios and teacher training.

The program is expected to serve 920 4-year-olds from families whose income is at or below 200 percent of the federal poverty guideline in areas with limited or no access to high-quality preschool. (This year the federal poverty guideline for Hawaii is $27,890 for a family of four.)

At risk is more than $10 million for the last two years of the grant, which would affect an estimated 720 children, said Tom Hutton, executive director of Hawaii’s Public Charter School Commission.

"It’s half of the life of the grant, but it’s disproportionate for us because we’re doing a phased-in implementation, so that third year is when it would really go to scale," Hutton said in an interview. "To pull the plug then, when we’re just at the cusp of making this have a larger impact on our state, would be really tragic."

Preschool in Hawaii has historically been provided by community-based organizations funded with philanthropic and federal support. About half of the state’s public school children enter kindergarten without a preschool education.

Hawaii voters in November 2014 rejected a constitutional amendment that would have allowed public funds to be used for private preschool programs. The amendment had proposed lifting the prohibition on public funds being used to support or benefit private educational institutions. It would have given the state the ability to use a combination of preschool classrooms at public schools and state- funded slots in private preschools to eventually serve all of the state’s 17,200 4-year-olds with a publicly funded preschool education.

Parents say their children are greatly benefiting from the early learning opportunities.

"With my daughter, I see a desire developing reading skills, learning her numbers, wanting to participate, self-awareness, developing her social skills around the other students (and) at home she is sharing more, using good manners," one parent wrote in a testimonial received by one of the participating charter schools.

Another parent said, "I have other children that did not attend preschool before kindergarten, and they struggled when they entered the classroom setting and even felt overwhelmed and out of place for a while."

Hutton said the commission’s staff has contacted Hawaii’s congressional delegation about the potential impacts.

U.S. Sen. Mazie Hirono, a longtime early childhood education advocate, said the funds are in jeopardy "because the Republicans don’t support this kind of program."

"I’m going to do everything I can to raise the awareness of the importance of this kind of grant because it supports evidence-based educational reform that really enables our kids to succeed in school and in life," said Hirono, a Democrat, in a phone interview from Washington, D.C. "There are actually Republican states that also are in the middle of these grants. And my hope is that these states that are led by Republican governors will also say, ‘Wait, you can’t just stop this funding midway for our kids.’"

The Preschool Development Grants program is contained in appropriations bills, separate from the two-year budget agreement.

"The appropriations process now needs to be redone, so that will be another bite at this apple to try to get it back into the bill now that the funding levels are different," said Betsy Lin, chief of staff for Hirono.