DES MOINES, Iowa (AP) — The Iowa House has begun debate on a bill that would ban most abortions in the state at 20 weeks of pregnancy.

The GOP-controlled chamber started debating Tuesday night. Republicans are expected to pass the legislation, which would be a victory for Iowa conservatives seeking to restrict abortion.

House Republicans expressed interest in changing the bill, which would require another vote from the GOP-led Senate. The Senate passed a version of the legislation last month. GOP Gov. Terry Branstad, who spoke recently at an anti-abortion rally at the Capitol, has indicated support for a 20-week ban. A spokesman says the governor reserves judgment on the legislation.

The ban on most abortions at 20 weeks of pregnancy is based on the disputed premise that a fetus can feel pain at that stage. Nearly 20 states have passed similar legislation in recent years.