Sixteen members of the University of Pennsylvania’s women’s swim team have sent a letter to school and Ivy League officials speaking out against transgender teammate Lia Thomas’ participation in the upcoming championship meets. They also ask the university and league to not take legal action against the NCAA if it adopts a policy barring Thomas’ eligibility.

The letter — penned by Nancy Hogshead-Makar, former Olympic swimmer and CEO of Champion Women, on behalf of 16 unnamed Penn swimmers and their families — appears to reveal a division in the team less than two weeks away from the Ivy League championship meet.

The players question the fairness of Thomas’ participation, and say that she is taking “competitive opportunities” away from other members of the team.

Thomas is a 22-year-old transgender woman who holds the fastest times of any female college swimmer in two events this season. She has been on gender hormone therapy for more than two years and has followed all NCAA eligibility requirements. Her times make her a favorite for the NCAA championship in March.

» READ MORE: A new policy on trans swimmers won’t affect Penn star Lia Thomas — for now

But her success has also made waves across the world of athletics, as critics, conservative media outlets, and even some of her teammates and their parents claim her male-at-birth assignment gives her an unfair advantage.

“We fully support Lia Thomas in her decision to affirm her gender identity and to transition from a man to a woman. Lia has every right to live her life authentically,” the letter reads.

“However, we also recognize that when it comes to sports competition, that the biology of sex is a separate issue from someone’s gender identity. Biologically, Lia holds an unfair advantage over competition in the women’s category, as evidenced by her rankings that have bounced from #462 as a male to #1 as a female. If she were to be eligible to compete against us, she could now break Penn, Ivy, and NCAA Women’s Swimming records; feats she could never have done as a male athlete,” they wrote.

Penn’s women’s team roster lists 41 members. The 16 teammates did not identify themselves in the letter, stating that they “have been told that if we spoke out against her inclusion into women’s competitions, that we would be removed from the team or that we would never get a job offer.”

Penn officials did not immediately respond for a request for comment.

Hogshead-Makar, a 1984 Olympic swimming gold medalist, said she began helping the swimmers and their parents write the letter about a week and a half ago after they felt silenced by the university.

“What’s most distressing to them is how the leadership is so focused on Lia, and not the 40 other members of the team,” she said.

She said the swimmers and parents are empathetic to the difficult situation Thomas faces, but “the fact that she is taking a place away from the other athletes is problematic.”

Only 18 members of the team are chosen to compete in the Ivy championships.

The father of a freestyle Penn swimmer who signed the letter, and who asked not to be named for fear of retribution against his daughter, said “there is this great frustration because the girls would go and express their concerns and feelings to the school, and the school tells them to get over it.”

The father said the team atmosphere is “not nearly as divisive as the media makes it out to be,” and that girls support her transition but want an equal shot at winning.

“I think Penn and the athletic department handled this case terribly. They never spoke to the girls, never listened to them,” said the mother of another Penn swimmer who signed onto the letter.

Hogshead-Makar said she has not received a response from Penn or the Ivy League. Parents of swimmers on other Ivy League teams have reached out asking for help writing a similar letter, she said.

On Monday, Penn Athletics released a statement on behalf of “several” members of the women’s team in support of Thomas. It did not name the athletes or specify how many signed it.

“We want to express our full support for Lia in her transition,” the statement said. “We value her as a person, teammate, and friend.”

Penn has not made coaches or swimmers available for interviews.

Earlier this week, USA Swimming released a new policy that, if adopted by the NCAA, could disqualify Thomas from competing in the NCAA championship in March.

The policy will require trans women athletes to submit an application to a three-person panel of “independent medical experts,” who will determine whether “prior physical development of the athlete as a male” gives the athlete “a competitive advantage.”

The swimmer must also show that their testosterone levels have been less than 5 nanomoles per liter continuously for at least 36 months.

Thomas has been on gender hormone therapy for 33 months.

But USA Swimming’s policy applies only to elite events and USA Swimming athlete members. NCAA events are not considered elite events and Thomas is not a member athlete.

The NCAA said a committee would review the change at a meeting later this month and make recommendations.

The Penn athletes’ letter asks Penn and the Ivy League to “support us as biological women, and not engage in legal action with the NCAA” to challenge the new policy if it’s adopted.

Thomas will likely be allowed to compete regardless of that meeting’s outcome because of the NCAA’s phased approach to its own new policy. For 2022 winter sport championships, like swimming, trans athletes must submit documentation showing they’ve undergone one year of testosterone suppressant treatment, and prove their testosterone levels are below 10 nmol/L, four weeks before the championship.

Thomas swam on the Penn men’s team for two years, before realizing she was trans in 2018, she has said.

She began hormone therapy in May 2019, and came out to her teammates that fall. She continued competing on the men’s team while taking the suppressants.

Thomas began submitting paperwork to the NCAA in summer of 2020, and was approved for eligibility. She did not swim at all last year, as the Ivy League season was canceled by the coronavirus pandemic. This is her first season on the women’s team.