The state Senate defeated a move Wednesday to repeal a Minnesota High School League policy that allows transgender students to use locker rooms and bathrooms that don't match their sex at birth.

The GOP-led House of Representatives passed an identical provision on Saturday, attaching it to an education policy bill on an unrecorded voice vote. But the DFL-controlled Senate voted it down 40-25 during debate on its own education policy measure.

Last December, the Minnesota High School League adopted a policy that opens up transgender student-athletes to participate in girls' sports. State law already lets female students participate in boys' sports. Since then, the Minnesota Family Council and other socially conservative groups have pushed for the locker and bathroom prohibitions.

"I believe, and believe parents believe, that biologically female students should not have to worry about a biological young man sharing their locker room or bathroom," said Sen. Warren Limmer, R-Maple Grove. "Nor should our daughters be put in a position of sharing a locker room or bathroom with a bunch of adolescent young men."

But Sen. Scott Dibble, DFL-Minneapolis, said such a prohibition would increase the stigma facing transgender students, and expose them to greater discrimination and physical violence.

"Gender identity is not a matter of choice or amenable to change," Dibble said.

The vote on the amendment fell largely along party lines, but with several crossovers. Sen. Lyle Koenen, DFL-Clara City, joined most Republicans in backing it. Three GOP senators -- Julianne Ortman of Chanhassen, and Carla Nelson and Dave Senjem of Rochester -- voted against it.

"This amendment makes me incredibly sad because it targets so very few Minnesotans," Ortman said. "I encourage members to be brave and vote no."

Since the House backed the measure, it will be up for debate in final House-Senate negotiations over the education policy bill. Gov. Mark Dayton has spoken in favor of the High School League policy, and has been critical of what he has called attempts to demonize transgender students.