Minnesota Gov. Mark Dayton pressed lawmakers on Tuesday to extend funding for preschool programs for the next three years, concerned one of his signature initiatives may fall by the wayside after he leaves office.

The Democratic governor has made expanding early learning options a top priority over his tenure, citing it as a means to close the state's wide education achievement gap between low-income and minority students. In 2013, Dayton and the Democratic-controlled Legislature created an all-day kindergarten program statewide. Republicans agreed to launch a voluntary preschool program in 2016.

And though the Legislature boosted funding for school districts to open preschool classes by $50 million last session, that money would lapse for the 2019-2020 school year. Flanked by principals from Minneapolis-area schools who've seen high preschool enrollment, Dayton urged lawmakers to give nearly 60 schools certainty that the funding would continue.

"It shouldn't be so hard to provide high-quality education for children who need it, who benefit from it and will be better for the rest of their lives because of it," Dayton said at a news conference Tuesday morning. "But here we are again, having to fight just to get the current level of funding for voluntary pre-kindergarten."

Dayton's proposal includes $57 million for those programs, which would cement early education programs for another three years. But Republicans who control the Legislature quickly raised questions over the governor's timing, saying school funding proposals should be addressed in a budget year. Lawmakers won't set a new budget until 2019 — after Dayton leaves office.

Republican lawmakers say the governor's proposal is premature and should be addressed next session.

"Whether or not it'll continue or continue in the same manner will be a question for the next governor and the next Legislature," said Eden Prairie GOP Rep. Jennifer Loon, who chairs the House Education Finance Committee. "But nothing's going to run out mid-budget."

Valley View Elementary principal Cori Thompson said if her school lost the $280,000 in funding it currently receives, it would slash preschool enrollment.

"It would hurt us. It would hurt our kids," she said, noting she has observed a more prepared kindergarten class after more than two-thirds of their students were enrolled in preschool programs at the Bloomington school.

Lawmakers plan to review childhood programs when a legislative auditor's report comes out next month. The report will evaluate various child education costs and coverage gaps around the state.

Sen. Carla Nelson, a Rochester Republican who chairs the Education Finance Committee, agrees that early education helps preschoolers transition to kindergarten. But she questioned whether daycares, community preschools or staying with family members are as effective for some children.