GREENWOOD, Ind. -- A central Indiana school district isn't calling off a planned high school graduation prayer unless a federal judge orders it.

Greenwood School Board president Joe Farley said the district wants the judge to decide the merits of a lawsuit filed by the school's top-ranked senior.

Video: The Rant: Should Schools Have Prayer At Graduation?

Greenwood High School student Eric Workman, 18, has asked a federal judge to stop a student-led prayer that the senior class voted to approve.

"(The vote) was unconstitutional," said Ken Falk, of the ACLU, last month. "You should never put someone's religious beliefs to a majority vote."

The lawsuit filed by the American Civil Liberties Union of Indiana on Workman's behalf claims that the prayer and class vote unconstitutionally subjects students to religious practice.

The school district has until April 16 to respond to the lawsuit, and a court hearing is scheduled for April 30.

The district's attorneys didn't immediately return telephone messages seeking comment Friday.

The American Family Association of Indiana opposes the legal challenge.

"We tolerate different points of view, but to silence people because you disagree with them is unfortunate," said spokesman Micah Clark in an interview with 6News last month.

Greenwood's graduation is set for May 28.

The U.S. Supreme Court ruled in 1992 that clergy-led prayers at public school graduations were unconstitutional.