Lesbian tennis champion Martina Navratilova has been nixed from Athlete Ally's roster of out sports figures after writing a controversial op-ed for London's Sunday Times.

In the op-ed, published last weekend, Navratilova argues that "letting men compete as women simply if they change their name and take hormones is unfair, no matter how those athletes may throw their weight around":

To put the argument at its most basic: a man can decide to be female, take hormones if required by whatever sporting organization is concerned, win everything in sight and perhaps earn a small fortune, and then reverse his decision and go back to making babies if he so desires. It’s insane and it’s cheating. I am happy to address a transgender woman in whatever form she prefers, but I would not be happy to compete against her. It would not be fair.

Navratilova competing at the French Open in 1975.

It's not the first time Navratilova, who broke barriers when she came out as a lesbian in 1981, has expressed trans-exclusionary views. The athlete got into a Twitter feud about her views, which was briefly addressed in the op-ed, reports The Advocate.

In a lengthy statement, prominent LGBTQ athletics advocacy group Athlete Ally confirmed that it has officially broke off its affiliation with Navratilova. (The group had previously approached her for clarification on her views on transgender athletes, but Navratilova never responded to their requests):

Public figures like Martina Navratilova have an incredible platform provided to them, and when they speak, the world listens. When we launched our Ambassador program in 2011 and invited Martina to join us, we saw her as a trailblazer for LGBTQ people in sports—someone who, like us, believed in the power of sport to advance equality, dismantle stereotypes, and build a more inclusive society. Martina’s latest statements stand in stark contrast to that vision, and to our core beliefs and values as an organization...

The trans community is under attack, and we firmly stand opposed to any and all people who perpetuate attacks against them—regardless of who they are or their accolades. To spread misinformation is to create a ripple effect of bias and discrimination that restricts trans people from living their lives fully, and endangers their health, safety and livelihood.

The choice confused some, including journalists, activists, and fellow tennis champ Billie Jean King, who chimed in on Twitter:

Meanwhile, Athlete Ally asserts that "the LGBTQ community is not a monolith," and "we must always leave space to learn from one another, and to grow. If we fail to do so, we are not only failing our goal to advance LGBTQ equality as a whole, but failing to live up to the core of our potential as human beings who believe all of us deserve a place in sports and in this world."