A federal appeals court says Mississippi can start enforcing a law that will let merchants and government employees cite religious beliefs to deny services to same-sex couples.

The 5th U.S. Circuit Court of Appeals on Thursday reversed a judge’s decision that had blocked the law before it could take effect last July.

U.S. District Judge Carlton Reeves had ruled that the law unconstitutionally establishes preferred beliefs and creates unequal treatment for LGBT people.

Republican Gov. Phil Bryant and other supporters say the law protects beliefs that marriage can be between only a man and a woman, and that a person’s gender is determined at birth and cannot be changed.

Gay and straight plaintiffs who sued the state say the law gives “special protections to one side” in a religious debate.

Robert McDuff is an attorney for some of the people who sued to try to block the law. He says that within two weeks, he will either ask the entire 5th Circuit to reconsider the panel’s decision or ask the U.S. Supreme Court to block the law.

Supporters say the law protects beliefs that marriage can be between only a man and a woman. Plaintiffs say the law gives “special protections to one side” in a religious debate.

The American Civil Liberties Union of Mississippi has filed a separate lawsuit challenging the law, House Bill 1523, which allows freedom of religion to justify discrimination against LGBT Mississippians and single parents.

“We are disappointed that the appeals court has reversed the preliminary injunction placed on HB 1523 and dismissed the case,” ACLU of Mississippi Executive Director Jennifer Riley Collins said in an emailed statement. “This decision places the plaintiffs and thousands more LGBT Mississippians and single parents in a position where they can be harmed for living as their authentic selves. This broad license to discriminate includes provisions that would seek to allow state employees to withhold marriage licenses from same-sex couples.”

Collins continued, “We are ready to move forward with our case filed on behalf of ACLU members Nykolas Alford and Stephen Thomas, who are planning to marry in Mississippi in the near future. That case was put on hold until the court of appeals ruled. We will continue to proceed on behalf of Nykolas and Stephen to protect them, and other same-sex couples from this harmful and discriminatory law.

“Freedom of religion is one of the most fundamental rights we have as Americans, but that freedom does not give any of us the right to harm or mistreat others.

Associated Press contributed to this report.