A group of Illinois students and parents sued the Obama administration Wednesday over its stance on transgender students’ access to school bathrooms and locker rooms, arguing that the U.S. Education Department is illegally forcing local authorities to let children use facilities that correspond to their gender identity.

The complaint alleges that the federal government has violated students’ fundamental right to privacy and parents’ constitutional right to instill moral standards and values in their children.

The lawsuit represents the first legal challenge to the Obama administration’s interpretation of Title IX, a federal anti-discrimination law, as providing transgender students with the right to use the bathroom that matches their gender identity instead of their biological sex.

[Feds say district broke law by banning transgender student from girl’s locker room]

The plaintiffs include female students who go to a high school that, under pressure from the Education Department, allowed a transgender girl to change in a girls locker room, according to the lawsuit, which concerns Palatine Township High School District 211.

The complaint says that the plaintiffs are afraid of seeing a “male in a state of undress” and “are afraid of being seen by, and being forced to share intimate spaces with, a male while they are in various states of undress.”

“Every day these girls go to school, they experience embarrassment, humiliation, anxiety, fear, apprehension, stress, degradation and loss of dignity because they will have to use the locker room and restroom with a biological male,” the complaint says.

The lawsuit was filed in U.S. District Court for the Northern District of Illinois with the support of two nonprofit legal advocacy groups, the Thomas More Society and the Alliance Defending Freedom.

The Obama administration’s push for transgender students’ access to the bathrooms of their choice has been cheered by LGBT activists, but it has also sparked a backlash from other advocates, parents and lawmakers who call it a federal overreach and an assault on traditional values and student privacy.

[Transgender students’ bathroom access is new front in battle over LGBT rights]

At least 14 states considered bills this year to limit transgender students’ access to school bathrooms, according to the Human Rights Campaign. A North Carolina law passed this year, which prohibits local authorities from extending civil-rights protections to gay and transgender people, has drawn fierce criticism from businesses and LGBT activists.

Meanwhile, transgender students have taken to the courts to fight for bathroom access. The U.S. Court of Appeals for the 4th Circuit recently sided with Virginia teenager Gavin Grimm, who sued after he was denied access to the boys bathroom at his school; the appeals court ruled that Grimm’s case must be allowed to go forward.

[‘We’re human beings.’ Transgender teen gratified by court’s ruling in bathroom case]

The plaintiffs in the new lawsuit are 51 families from Palatine, Ill., where the U.S. Education Department last year found schools in violation of Title IX because of their policies on locker room access.

The Palatine school system, as well as the federal departments of education and justice, are named as defendants.

Palatine officials — facing the loss of $6 million in federal funding — ultimately decided to allow a transgender student to change in the girls locker room instead of sending her down the hall to a separate facility.

The dispute led to emotionally charged public meetings that drew crowds of parents who opposed the federal government’s position and wanted to see their school board stand its ground.