Reps. Tulsi Gabbard (D-Hawaii) and Markwayne Mullin (R-Okla.) introduced legislation that would ban male-born athletes from competing in women and girls' sports.
The proposed bill, known as Protect Women's Sports Act, seeks to clarify that Title IX, the federal law prohibiting sex discrimination in federally sponsored programs, applies based on biological sex.
If passed, the bill would make it a Title IX violation for schools and colleges that receive federal funding to "permit a person whose biological sex at birth is male to participate in an athletic program or activity that is designated for women or girls."
"Title IX was a historic provision championed by Hawaii's own Congresswoman Patsy Mink in order to provide equal opportunity for women and girls in high school and college sports," Gabbard, a former contender for the Democratic presidential nomination, said in a statement.
"However, Title IX is being weakened by some states who are misinterpreting Title IX, creating uncertainty, undue hardship and lost opportunities for female athletes," Gabbard continued. "Our legislation protects Title IX's original intent which was based on the general biological distinction between men and women athletes based on sex."

Mullin said in a separate statement that allowing "biological males" to compete in women's sports "takes away from the original intent of Title IX."
"As the father of three girls involved in athletics, I want them to be able to compete on a level playing field," he said. "I am proud to lead this bill that will safeguard the integrity of women's sports and ensure female athletes can compete fairly."
The bipartisan bill comes after the Education Department resolved a Title IX complaint against Franklin Pierce University (FPU) in New Hampshire. Under the resolution agreement, the FPU is required to rescind its 2018 policy for school sports, which allowed transgender student-athletes to participate on women's sports teams after one year of testosterone-suppression treatment.
"Transgender policies have turned Title IX on its head, denying the rights of women and girl athletes to compete only against athletes of the same sex and threatening the future of women's sports," said Penny Nance, CWA's CEO and president.