On Thursday, the Missouri Senate gave final approval to a bill that seeks to give broad legal protections to opponents of marriage equality.

Democrats attempted to block the bill with a marathon filibuster, but after 39-hours Republicans used a procedural move to break the filibuster and ultimately approve the bill.

Senate Joint Resolution No. 39 now heads to the House.

Governor Jay Nixon, a Democrat, condemned the legislation on Wednesday.

“Rewriting our state’s constitution to condone discrimination would be contrary to our values and harmful to our economy,” Nixon wrote in a statement. “That’s why Missourians across the state, including business leaders and clergy, have spoken out strongly against SJR 39. I applaud the historic effort by the Senate minority to block this resolution and urge members of the House to protect the rights of all Missourians by opposing this discriminatory measure.”

The proposed constitutional amendment could go before Missouri voters as soon as November if approved by the Republican-led House.

The bill would protect religious groups when acting “in accordance with a sincere religious belief” about same-sex marriage. Schools, charities and even retirement homes are among the businesses that could qualify as religious organizations under the bill.

Opponents believe the bill could be used to deny housing, employment and social services to gay and lesbian people who are married.