A federal lawsuit was filed Friday on behalf of two openly lesbian members of Champlin Park High School's Snow Days royalty who want to walk into a pep fest Monday as a couple.

The suit is the most dramatic development in a controversy sparked by the school's decision to change its tradition of having the 24 members of student royalty walk in as couples, boys paired with girls. Instead, the students will walk in individually, accompanied by a parent, teacher or other adult mentor.

The students at the center of the tempest -- seniors Desiree Shelton and Sarah Lindstrom -- did not initiate the lawsuit. It was filed Friday in U.S. District Court in Minneapolis on their behalf by representatives of the Southern Poverty Law Center, the National Center for Lesbian Rights, and the Faegre & Benson law firm.

The school says it's just trying to make everyone as comfortable as possible and to prevent any possible heckling in the face of a situation it hasn't experienced before. But on Friday, some students charged that it is discriminating against gay and lesbian students.

Students elect the 24 members of the Snow Days royalty. Twelve seniors and four students from each of the Brooklyn Park school's other three grades, equally divided between boys and girls, are chosen.

Junior Justin Christoffer had an opinion as school let out Friday: "To be honest, I think [the school's decision] is kind of stupid. They say we're not supposed to discriminate based on sexual orientation, and when they changed things, they just did that."

Anoka-Hennepin School District officials said the decision was made to stress that students should be honored as individuals, and not by sexual preference. Champlin Park Principal Michael George made the call earlier this week after consulting with district officials, said district spokeswoman Mary Olson. George could not be reached for comment Friday.

Olson said the feeling behind the decision was "just that this would be more comfortable for everyone.

"The thought was that the old approach was an assumption that everyone in royalty was heterosexual when that might not be the case," she said. "By doing [the procession] the individual way, there is no assumption that they're heterosexual or homosexual; they're simply Champlin Park students being selected as royalty."

She said the change was not the result of any complaints, and had created no big hubbub in the school. "My understanding is that there is a difference of opinion, but that most students are fine with that," she said.

Some students said otherwise on Friday.

"If an African-American and a white person wanted to walk together, there would be no objection at all," said junior Shannon Haver. "In every class we have a ... thing that says you cannot discriminate because of race, religion, ethnicity, sexual orientation, age or ability. They're in every classroom. But the fact that they're not following what they teach is going to create an environment [among students] where, they're thinking, 'If they don't have to, we don't have to.'"

Shelton said she and Lindstrom still plan to be at the pep fest, but weren't sure how they were going to handle the procession.

"Right now, I really don't have an answer for that," she said. "We will be in the whole thing, we just don't know how it's going to work. ... I never thought it was going to be a big deal. But when they turned us down, I was disappointed."

Lindstrom declined to comment.

Not all students were foursquare behind Shelton and Lindstrom.

"I think it should be the traditional way like they've always had it," said junior Nick Stadler. "Personally, I'm against [Shelton and Lindstrom walking together]. But I don't really care. I have a few friends who are gay and lesbian."

English teacher Jann Garofano said that she didn't have a problem with the school doing away with the procession of paired students, but that the timing made her cringe.

"I think it's fine to recognize people as individuals," she said. "But why couldn't they have done that before this?"

Haver said students who favor letting Shelton and Lindstrom walk together plan to wear red shirts to the pep fest and carry supportive signs. She said there are no plans to try to disrupt the ceremonies.

Mary Bauer, legal director of the Southern Poverty Law Center, one of the groups that brought the lawsuit, said, "It's kind of astonishing that two girls walking together is so shameful and terrible for other people to witness" that the event would be altered. Bauer said a hearing on the suit is scheduled for Monday morning. The Associated Press reported that a mediation session was set for Saturday morning.