A Department of Education official said the district violated Title IX, the federal civil rights law that bars discrimination based on sex, by creating all-gender bathrooms and allowing students to use the bathroom they feel most closely identifies with, rather than their sex at birth.

The office, led by Acting Assistant Secretary for Civil Rights Craig Trainor, started an investigation into the policy in January after the district changed the sex of a restroom at East High School from all-girls to all-gender.

District officials at the time said the restroom decision went against the federal guidelines on Title IX.

As part of a student-led decision, Denver Public Schools decided to redesign a restroom at East High School to make it an all-gender restroom, but kept one restroom across the hallway for boys only.

School district leaders said the decision came from a student-led process and that in the new all-gender bathroom there were 12-foot-tall partitions around toilets to help protect the safety and privacy of students.

The federal government disagreed.

The Department of Education determined that the policy change violated Title IX. In a statement on Thursday, Trainor said the bathroom change left students without equal access to facilities on campus and created a “hostile environment.”

The district created a second all-gender bathroom on the same floor to help remedy the fairness issue. District leaders said students were able to use the other single-sex bathrooms on campus as well as single-stall, all-gender restrooms.

On Thursday, the federal government sent the district a proposed resolution with four provisions they would have to agree to in order to resolve the issue. The district will have 10 days to decide to agree with the resolution and make the changes. If not, the federal government will take enforcement action, including the removal of federal funding.

The resolution proposed to the district includes four provisions the district would have to make in order to comply with federal Title IX guidelines on gender.

The resolution would require Denver Public Schools to:

Change the sex of all all-gender multi-stall restrooms back to male or female only.

Eliminate restroom policies for students to use bathroom based on their gender identity rather than biological sex.

Define “male” and “female” under “biology-based definitions” for Title IX-related policies.

Send a memorandum to district schools that “all intimate facilities at District schools will be maintained and operated so that they protect the privacy, dignity, and safety of students and will be comparably accessible to students of each biological sex.”

In a press release on Thursday, Trainor called out the district for policies that “endanger student safety, privacy, and dignity.”

“Denver Public Schools violated Title IX and its implementing regulations by converting a sex-segregated restroom designated for girls in East High School to an ‘all-gender’ facility and by allowing students to use the high school’s intimate facilities on the basis of their gender identity rather than their biological sex,” Trainor said.

“Denver is free to endorse a self-defeating gender ideology, but it is not free to accept federal taxpayer funds and harm its students in violation of Title IX,” Trainor said. “The Trump Administration will work relentlessly to hold accountable school districts that harbor the ideological fanatics and policies that sully students’ educational experience with sex discrimination.”

District leaders have maintained that the bathroom decision was made by a student-led process and that the all-gender restrooms were put in place to meet student needs.

District officials have not yet publicly responded to the resolution proposed on Thursday by the Department of Education, but previously said that students can continue to use all the other bathrooms on campus, including single-stall, all-gender restrooms if they prefer.

The debate is playing out in Denver as President Donald Trump signed an executive order this year that prevents transgender girls from playing on girls sports teams. Republican leaders in Congress have also been trying to pass legislation that would prevent transgender students from using the bathrooms or playing on teams that reflect their gender identity.

The Trump administration and Education Department have also been cracking down on other instances of alleged gender discrimination at schools and universities over similar issues. This week, the Department of Education said George Mason University’s diversity, equity, and inclusion (DEI) policies violated federal law.

Denver Public Schools leaders have 10 days to either comply with the proposed resolution and undo all-gender bathrooms or risk enforcement action by the Department of Education, which could cost the district millions of dollars in federal funding.

District leaders now have to decide if they will continue with their all-gender bathroom policies or if they will roll back the policy and return to single-sex bathrooms only.