Americans United for Separation of Church and State, a religious liberty watchdog group, filed a federal lawsuit Friday against the Medina Valley Independent School District, alleging that the district will illegally include prayer during its June 4 graduation ceremony.

The group said it filed the lawsuit on behalf of a local family after district officials refused to remove a student-led invocation and benediction, according to a news release.

The district disagrees, stating that plans for student remarks at the ceremony do not violate any laws or school policy.

The school board president, in a statement Friday, said the district is “aware of the fine balancing act” required of the First Amendment rights of speech and religion and has set a neutral policy.

On the contrary, the district is in violation of Supreme Court rulings, the lawsuit states.

“Public schools can't require students to take part in religious worship as the price of attending their graduation,” the Rev. Barry W. Lynn, executive director of Americans United, said in a statement. “This is settled law, and the district needs to stop resisting it.”

The lawsuit was filed on behalf of Christa and Danny Schultz, who have two children in the district, including a son scheduled to graduate next week from Medina Valley High School.

In October 2010, the couple's lawyers wrote to district officials asking them to stop plans for public prayers during school events. According to the release, officials didn't respond to the request.

The Schultzes attended the graduation of a family friend in 2008, “where they were exposed to unwelcome prayers,” the lawsuit stated, and it happened again in 2009 when their eldest child graduated.

The son said he might not attend the ceremony if prayers are included, according to the release.

“They're not atheists, they're actually agnostic, and (the parents) don't believe a school-sponsored prayer should be part of a school-sponsored event,” said Don Flanary, the San Antonio attorney for the group and the family.

The lawsuit requests a temporary order barring the district from sponsoring prayers during graduation and a permanent injunction barring prayers at future school events. A hearing is scheduled for Tuesday in San Antonio.

Roland Ruiz, school board president, said that allowing students to express their own religious views doesn't mean the district is sponsoring religious activity.

“A disclaimer is printed in each graduation program that notes the content of each student speaker's message is the private expression of the individual student and does not reflect the endorsement of the district,” he said.

“It is sad that someone would choose the commencement exercises of the 50th anniversary of our school district as a forum for stirring political debate that threatens to needlessly cast a shadow of controversy over the pinnacle event of the class of 2011.”

In 1992, the Supreme Court ruled that public schools cannot impose prayer and religious worship on students and their families at commencements, according to Americans United. The suit references the “pervasive religiosity” in the school, stating that Principal Toby Tyler regularly makes religious statements over the school's loudspeaker.