Gov. Mark Dayton called on the Legislature Tuesday to use some of the state surplus to make permanent a one-time $50 million investment in prekindergarten that lawmakers approved last year.

Dayton said that without $57 million in the next two-year budget, parents and teachers of 4,000 preschoolers in 59 school districts would not be able to rely on prekindergarten in the fall of 2019.

"We cannot let these programs expire for 4,000 kids, their younger siblings, and their families," Dayton said at a news conference, flanked by educators, his education commissioner and state Sen. Greg Clausen, DFL-Apple Valley.

"Alarmist nonsense," said Andrew Wagner, a spokesman for House Republicans, in a response on Twitter.

The program, which now serves a total of 6,100 students in 109 school districts, has been funded through this school year and next, but a chunk of its current budget was a one-time cash infusion that the Legislature needs to repeat next year at the latest, or the school districts would be without money for the program beginning July 1, 2019.

Although Dayton eschews talk of a legacy, the second-term DFL governor showed he wants to fight for a record that will outlast his tenure, which ends in fewer than 300 days. Expanding prekindergarten offerings at public schools has been a central priority for Dayton in his second term.

Rep. Jenifer Loon, R-Eden Prairie, who chairs the House Education Finance Committee, said in a statement that House Republicans share Dayton's commitment to early childhood education, which is why they spent the money in the first place. In addition to the school-based prekindergarten, the state spends money on scholarships for private schools and other programs, bringing the total spent on various early learning programs to $262 million, serving 22,500 students.

Loon said the Legislature will discuss the 2019-2020 school budget with the governor — just not this one: "We look forward to a robust discussion with Gov. Dayton's successor about this and all other budget items when the next Legislature convenes in January 2019."

The evidence for the success of early childhood education is mixed.

In a program called the Abecedarian Project, a study of early learning participants at age 30 found they were more likely to achieve a bachelor's degree, hold a job and delay parenthood than their peers. A University of Minnesota study of 1,398 children up to 35 years of age showed a 48 percent higher rate of completing an associate degree or higher compared to their peers.

Other studies have failed to show the same positive outcomes. A recent Vanderbilt University study showed that positive outcomes for pre­kindergarten students faded by the end of kindergarten.