A coalition of civil rights groups sued Oklahoma on Tuesday over laws limiting instruction on race and gender issues.

Led by the American Civil Liberties Union (ACLU) of Oklahoma and the Lawyers Committee for Civil Rights Under Law, the coalition is seeking to block implementation of H.B. 1775, which outlaws the teaching of critical race theory.

“H.B. 1775 is an unlawful intrusion by politicians into the classroom — without input from educators — that dictates not just what can be taught, but how teachers must teach in service of an avowedly political agenda,” the complaint states. 

Oklahoma Gov. Kevin Stitt (R) signed the bill in May to prevent schools from teaching the academic theory that holds that racism is ingrained in the history of the U.S. and still impacts laws and institutions. 

Conservatives have railed against the teaching of critical race theory, often expanding the term to describe any discussion about race in classrooms.

While Oklahoma is one of eight states that have passed laws restricting lessons involving race and gender, Tuesday’s lawsuit is the first seeking to challenge one of them, the ACLU said in a statement. 

Because of the law, teachers are “blacklisting books by diverse authors” and otherwise adjusting their lessons to avoid questions about race and gender.

The plaintiffs allege that the law “severely restricts discussions on race and gender in Oklahoma’s elementary, secondary, and higher education schools without any legitimate pedagogical justification, using language that is simultaneously sweeping and unclear.”

The law “prohibits opportunities for free debate and discussion, and is overbroad, vague and viewpoint discriminatory,” the complaint states.

“It’s par for the course that when something goes against the left’s liberal agenda activist groups attempt to come into Oklahoma and challenge our laws and our way of life,” Stitt’s communications director Carly Atchison told The Hill in a statement.

“But Governor Stitt stands by his decision to sign HB1775 and ban teaching our children that one race or sex is inherently superior to another race or sex,” she continued.

Upon signing the bill, Stitt said, “As governor, I firmly believe that not one cent of taxpayer money should be used to define and divide young Oklahomans about their race or sex.”

Updated: Oct. 20 at 11:07 a.m.