"Parents have a right to expect that the public schools will remain absolutely neutral in religious matters," Pevar said. "Parents who wish to have prayer in school should place their children in private schools."

The American Civil Liberties Union has made good on its threat to sue the Madison School District over prayer at school activities.The ACLU filed a lawsuit Friday in U.S. District Court in Boise on behalf of two Madison County families. They claim the district is violating their constitutional rights by allowing prayer at graduation ceremonies and before athletic events.

The plaintiffs are listed as Jane Doe and her two children, X and Y Doe, and David and Diane Roe and their child, R Roe.

ACLU attorney Stephen Pevar of Denver said the suit was filed because the district is violating a prohibition against public schools being used as vehicles for religious teaching or activities.

"Parents have a right to expect that the public schools will remain absolutely neutral in religious matters," he said. "Parents who wish to have prayer in school should place their children in private schools."

Ann Hancock, chairman of the Madison School Board, said she would not comment on the lawsuit until it is served by a federal marshal.

"Our problem is they have been threatening this so long," she said. "It is not appropriate for us to comment until it is official."

The school board has tentatively scheduled a meeting Tuesday to respond to the lawsuit. Hancock and four others filed their complaint anonymously because they fear being ostracized in the predominantly Mormon community. He said they would withdraw the suit if a judge rules they must be identified.

"The parents and the children both fear reprisal and harassment from people in the community or within the school," Pevar said.

The ACLU first threatened suit against the district in June after several families complained that the relationship between the Rexburg schools and The Church of Jesus Christ of Latter-day Saints violates the constitutional separation of church and state.

In response, the Madison School Board agreed to halt some practices, such as allowing Mormon seminary instructors to conduct parent-teacher conferences in the schools. But it said it would continue allowing student-initiated, student-led prayer at graduations and in locker rooms before athletic events.

School officials, hoping to avoid a costly legal battle, also agreed to abide by court decisions over prayer issues pending in Utah. The ACLU has brought similar suits against Granite and Alpine districts in Utah in an attempt to ban prayer in that state's 40 school districts.

Granite and Alpine contend banning graduation prayers would deprive students of their constitutional rights to free speech. The ACLU contends the districts' purpose in having prayers is to advance or endorse religion, and it is wrong to use public funds to promote prayer.