A Utah parent has sued the school district of her two children after it pulled a book about a lesbian couple from the shelves of an elementary school library.

In a federal class action, Tina Weber is challenging the constitutionality of the Davis School District library’s decision to restrict access to “In Our Mothers’ House,” an illustrated children’s book by Patricia Polacco, which centers on a lesbian couple who face discrimination as they raise their three children. The book, published in 2009 by Penguin’s Philomel imprint, is still available at the library but only by request.

In April, the school district pulled the book from its shelves and placed it behind a counter after some parents complained that it promoted a homosexual lifestyle. According to the lawsuit, one parent wrote at the time: “I don’t agree that wholesome complete parenting can be done by lesbians without a father role. It’s not a natural process to have a complete family without a male and female.”

The lawsuit, filed Tuesday in U.S. District Court and reported by Courthouse News Service, argues that the library has overstepped its bounds. “Over 30 years ago, the Supreme Court held that school officials may not remove books from school library shelves because they or their constituents disagree with the ideas those books contain,” the complaint states. “The District can respect the wishes of parents who disagree with ‘In Our Mothers’ House’ by allowing parents to place limits on their own children’s ability to check out particular books.”

According to Reuters, the school district has confirmed that no similar restrictions have been placed on other books.

“We still feel very comfortable with the process we followed, which is laid out in district policy," Chris Williams, a spokesperson for the school district, told Reuters. "Parents still have the opportunity, if they want their child to read the book, to get it. It’s not on the shelves, but it’s accessible.”

The state of Utah has laws on the books that prohibit homosexual advocacy in public schools. The Davis School District, which is 24 miles north of Salt Lake City, has argued that keeping “In Our Mothers’ House” on its library shelves would violate those laws.

About 40 percent of Salt Lake City residents are Mormon. The Church of Latter-Day Saints, which is headquartered there, is widely considered to be one of the most vocal proponents of California’s Proposition 8, the 2008 ballot initiative stipulating that “only marriage between a man and a woman is valid or recognized.” The faith places an unusually strong emphasis on reproduction. 

Weber’s lawsuit was filed on behalf of lawyers for the American Civil Liberties Union, which said in the complaint that restricting the book violates the free-speech rights of her children. “Even worse,” the lawsuit adds, “segregating it from the rest of the library collection places an unconstitutional stigma on the book and the students who wish to read it.”

The ACLU is seeking class-action status for the case. No hearings have been scheduled.