The nation’s largest publisher and several bestselling authors, including novelists John Green and Jodi Picoult, are part of a lawsuit filed Thursday challenging Iowa’s new law that bans public school libraries and classrooms from having practically any book that depicts sexual activity.

The lawsuit is the second in the past week to challenge the law, which bans books with sexual content all the way through 12th grade. An exception is allowed for religious texts.

Penguin Random House and four authors joined several teachers, a student and the Iowa State Education Association — the state’s teachers union representing 50,000 current and former public school educators — in filing the federal lawsuit.

The law went into effect this fall after the Republican-led Legislature passed it earlier this year and Gov. Kim Reynolds signed it in May. In addition to the the book ban, the law forbids educators from raising gender identity and sexual orientation issues with students through grade six, and school administrators are required to notify parents if students ask to change their pronouns or names.

It is the portion banning books that the latest lawsuit challenges, said Dan Novack, an attorney for and vice president of Penguin Random House. That ban prohibits books that feature any description or depiction of sex — regardless of context or whether the work is fiction or nonfiction — from schools and classroom libraries from kindergarten through grade 12.

“It’s also created the paradox that under Iowa law, a 16-year-old student is old enough to consent to sex but not old enough to read about it in school,” Novack said.

The law also bans books containing references to sexual orientation and gender identity for students through sixth grade, which the lawsuit says is a violation of the 14th Amendment’s equal protection clause.

The lawsuit seeks a court order declaring the law unconstitutional, Novack said, adding that government can’t violate free speech rights “by pretending that school grounds are constitutional no-fly zones.”

The lawsuit does not seek monetary damages.

Schools already have in place systems that allow parents to object to their children reading books the parents find objectionable, said Mike Beranek, president of the Iowa teachers union.

“We take issue with a law that also censors materials for everyone else’s child,” he said.

Asked for comment on the lawsuit, Reynold’s office referred to her statement issued earlier this week in response to a separate lawsuit by the American Civil Liberties Union and Lambda Legal on behalf of several families challenging the entirety of the new law. In that statement, Reynolds defended the law as “protecting children from pornography and sexually explicit content.”

Plaintiffs in the latest lawsuit took issue with that characterization, noting that among books that have been banned in Iowa schools are such critically acclaimed and classic works as “The Color Purple” by Alice Walker, “Native Son” by Richard Wright and “1984” by George Orwell, showing that under the law, “no great American novel can survive,” Novack said.

Novelist Laurie Halse Anderson, a plaintiff in the lawsuit whose book “Speak” about a young teenage rape victim has been banned from several Iowa schools, was more blunt.

“I think that anybody who finds a book about a 13-year-old rape survivor as being pornographic needs some professional help,” Anderson said.