JACKSON, Mississippi -- Mississippi Gov. Phil Bryant signed a bill Thursday that could lead to student-led prayer over school intercoms or at graduations or sporting events. The American Civil Liberties Union said the measure, which becomes law July 1, is likely to prompt a lawsuit in the school year that begins in August.

Republican Bryant was joined by about two dozen lawmakers, ministers and other supporters as he signed Senate Bill 2633. His grandmother's Bible, with a black leather cover and well-worn pages, sat on the desk of his Capitol office.

"We believe that we're on firm ground here with our opportunity for religious expression in a limited forum within public schools. That does not mean that they won't file a lawsuit, and we'll see how that comes out for us," Bryant said.

The new law says all Mississippi school districts must adopt a policy to allow a "limited public forum" at school events such as football games or morning announcements, to let students express religious beliefs. The policy must include a disclaimer that such student speech "does not reflect the endorsement, sponsorship, position or expression of the district."

Bear Atwood, legal director for ACLU of Mississippi, did not attend the bill signing ceremony but told The Associated Press in a phone interview that she thinks the law "has serious constitutional issues." She said the ACLU will wait to see if there's proselytizing in public schools before deciding whether to file a lawsuit.

"At the end of the day, do I think there will be a legal challenge?" Atwood said. "Yes, which is unfortunate because it is not the governor or the Legislature that will get sued but the individual school district and that's not a very good way for them (to) spend their limited education dollars -- especially given that this is a pretty well-settled area of law."

Bryant, who often talks about cutting government spending, said: "If we've got to spend taxpayers' money, I think we would be honored to spend it in defending religious freedoms for the people of the state of Mississippi."

The governor said Attorney General Jim Hood, a Democrat, would be responsible for defending the state.

"I think he's very capable of doing that and we look forward to working with him," Bryant said.

The law also specifies that students are allowed to express religious beliefs in their class assignments and are free to organize religious groups on campus. Atwood said it's already "well-established constitutional law" that students have the right to do those things and to wear clothing with religious expression or gather around a public school flagpole to pray.

"There's plenty of guidance for schools," Atwood said. "This bill is about trying end-run the Constitution so there can be prayer over the loudspeaker during school day and school assemblies and sporting events and graduations ... Students have the right to engage in voluntary prayer as long as it's not disruptive to the school environment, which is the same as all of their First Amendment rights."

The Rev. David D. Tipton Jr., superintendent for the Mississippi District of the United Pentecostal Church, was among those attending the bill signing. He said he believes there are barriers to religious expression in public schools.

"We have listened to the argument of the separation of church and state too long, and those barriers, I believe, is a facade with a certain agenda that has actually I think brought our nation to the peril that it is in," Tipton said. "So, yes, there are barriers there that a person or a child is afraid to speak anything related to God or Jesus because of lawsuits and things like that. So I think this piece of legislation will be a positive thing for the state of Mississippi."