AUSTIN (AP) — Facing a midnight deadline, the Texas House has started debate on whether to allow concealed handguns in public college classrooms and buildings.

The measure sailed through the Republican-controlled Senate in March, but wasn’t set for a vote in the House until the final week of the legislative session. If approved there, it goes to Gov. Greg Abbott to sign into law.

Abbott has pledged to expand gun rights in his first session as the state’s chief executive.

But the bill faces a midnight deadline to pass the House and the chamber began the debate with just over three hours to go and more than 100 amendments set for consideration.

Gun rights groups call it a self-defense measure for students and teachers. Opponents say it will make campuses less safe.