Advocates of same-sex marriage said Monday that they will ask the U.S. Supreme Court to strike down a Mississippi law that lets government workers and business people cite their own religious objections to refuse services to gay couples.

The law, considered the broadest religious-objections law enacted since the U.S. Supreme Court legalized same-sex marriage in 2015, has been on hold amid court challenges. But it is set to take effect Friday because a federal appeals court refused to keep blocking it.

Championed and signed by Republican Gov. Phil Bryant in 2016, the law protects three beliefs: that marriage is only between a man and a woman, sex should only take place in such a marriage, and a person's gender is determined at birth and cannot be altered.

"This is an unfair and unconstitutional law," said Robert McDuff, an attorney for some of the gay and straight Mississippi residents who sued to try to block it.

The Mississippi law would allow clerks to cite religious objections to recuse themselves from issuing marriage licenses to same-sex couples, and would protect merchants who refuse services to LGBT people. It could affect adoptions and foster care, business practices and school bathroom policies.

The Supreme Court will hear a case this term about a Colorado baker who said he should not be forced to violate his own religious beliefs by making a cake for a married same-sex couple. The Trump administration is supporting the baker, who disagreed with a Colorado law that bars discrimination on the basis of sexual orientation.

The Mississippi law would affect actions by government workers and people working for private businesses.

U.S. District Judge Carlton Reeves blocked the Mississippi law from taking effect in July 2016, ruling it unconstitutionally establishes preferred beliefs and creates unequal treatment for lesbian, gay, bisexual and transgender people.

A panel of judges from the 5th U.S. Circuit Court of Appeals lifted the hold on the law June 22, saying people who sued the state had failed to show they would be harmed. Plaintiffs asked the whole appeals court to reverse that decision, but the court said last Friday that it would not do so. That opens the way for the law to take effect in Mississippi.

McDuff, the Mississippi Center for Justice and the gay-rights group Lambda Legal are asking the Supreme Court to reverse the 5th Circuit's action.

The law "creates a toxic environment of fear and prejudice," Susan Sommer, director of constitutional litigation for Lambda Legal, said in a statement Monday. "Along with other anti-LGBT laws across the country like those in North Carolina and Texas, these laws are a pack of wolves in sheep's clothing, dressing up discrimination and calling it religious freedom."

An Arizona-based Christian group, Alliance Defending Freedom, helped write the Mississippi law.

"As I have said from the beginning, this law was democratically enacted and is perfectly constitutional," Gov. Bryant said Monday. "The people of Mississippi have the right to ensure that all of our citizens are free to peacefully live and work without fear of being punished for their sincerely held religious beliefs."