A federal judge in Louisiana on Thursday blocked President Joe Biden's administration from enforcing in four states a new rule that protects LGBT students from discrimination based on their gender identity in schools and colleges.

U.S. District Judge Terry Doughty in Monroe issued a preliminary injunction, barring a U.S. Department of Education rule that extended sex discrimination protections under Title IX to LGBT students from taking effect in the Republican-led states of Louisiana, Mississippi, Montana and Idaho.

Those states had argued that unless the rule was blocked, schools would be required to allow transgender students to use restrooms and locker rooms conforming to their gender identities.

"Enacting the changes in the final rule would subvert the original purpose of Title IX: protecting biological females from discrimination," Doughty, an appointee of Republican former President Donald Trump, wrote.

The ruling was the first by a judge blocking the rule, which had been challenged in nine lawsuits by Republican-led states and conservative activists who argue it amounts to an unlawful rewrite by the Democratic president's administration of a law designed to protect women from discrimination in education.

"This is a big win for women's rights," Montana Attorney General Austin Knudsen, a Republican, said in a statement. "This decision will keep young women and girls protected from dangerous situations, just as Title IX has done for decades."

Kelley Robinson, the president of the LGBT rights group Human Rights Campaign, in a statement said students deserve protection from bullying, misgendering and abuse yet the case had the "dangerous goal of weaving discrimination into law."

The other lawsuits remain pending. The rule is set to take effect Aug. 1. The Education Department did not respond to a request for comment.

The department in issuing the rule in April said it clarified that the prohibition against sex-based discrimination in schools and colleges that receive federal funding contained in Title IX of the Education Amendments of 1972 also includes discrimination based on sexual orientation and gender identity.

The department cited a 2020 U.S. Supreme Court decision holding that a ban against sex discrimination in the workplace contained in a different law, Title VII, covered gay and transgender workers.

Courts often rely on interpretations of Title VII when analyzing Title IX as both laws bar discrimination on the basis of sex.

But Doughty agreed with the Republican state attorneys general of Louisiana, Mississippi, Montana and Idaho that the rule was "inconsistent with the text, structure, and purpose of Title IX."

Doughty said the rule would require schools to use whatever pronouns a student preferred and allow them to access bathrooms and locker rooms based on their gender identity, an issue of political significance the agency lacked authority to address.

He said it also ran afoul of the U.S. Constitution's Spending Clause by containing ambiguous conditions and violating other constitutional provisions, including the First Amendment's protections for free speech and the free exercise of religion.