Teacher seniority remains the biggest factor for teacher layoffs.

Gov. Mark Dayton has vetoed a bill that would have let schools lay off teachers based on their performance rather than simply seniority.

Dayton vetoed the bill Thursday, writing in a veto letter that the bill shows prejudice against public school teachers. He says it replaces the most prevalent system of determining teacher layoffs with what he called “vaguely formulated ideas.”

Under current law, schools must only consider seniority in layoff decisions. The only exception is districts that negotiate their own policies.

The bill wouldn’t have affected Austin Public Schools in coming years, as the district is projected to gain students for several years and most likely wouldn’t be in a situation to lay off teachers.

“For us, it really wouldn’t have meant much of a change,” said Mary Burroughs, Austin’s director of human resources.

Burroughs said the bill in its current form would need to rely on empirical teacher evaluations. Legislators included a new statewide teacher evaluation system in last year’s omnibus education bill, but the new mandates have yet be revealed in detail.

“You have to have a very good performance management system in place,” for the bill to work, Burroughs said. Otherwise, the bill would have allowed districts to lay off teachers based on “feelings on which teacher is better without that data.”

The bill’s chief House sponsor, Republican Branden Petersen of Andover, says he tried to work toward a bill Dayton would sign but made no progress after four separate meetings with the governor. He accused Dayton of siding with union special interests over students.

Rep. Jeanne Poppe, DFL-Austin, believes Dayton made the right choice to veto the bill before the state’s teacher evaluation system is in place. She also believed the bill would take more power out of local district control while adding another state mandate.

“That bill was not quite ready for prime time,” she said.

Education Minnesota issued a statement Thursday supporting Dayton’s veto.

“Gov. Dayton said in his State of the State speech that education policy shouldn’t be a political ploy and he promised to veto anything that was,” Education Minnesota President Tom Dooher said in a press release. “He kept that promise today and our 70,000 educators thank him for it.”

—The Associated Press contributed to this report.