Martina Navratilova has doubled down on her stance regarding the ongoing trans-athlete debate as she engaged in a Twitter argument with English Professor Grace Lavery.

59-time Grand Slam champion Navratilova has been vocal about the debate around trans women in sports for some time now. Whilst the 66-year-old has stated that she doesn't want to ban trans people from competing, she has previously expressed her desire for people to, in her words:

"compete in the biological category rather than a self ID category."

This view opposes the likes of Billie Jean King and Megan Rapinoe, who have defended the inclusion of trans women in the women's category.

The topic came up once again for Navratilova, as she got herself into a heated argument with Grace Lavery, an English professor at the University of California, Berkeley.

It began when the former world No. 1 responded to a tweet from the professor which read as follows:

"Feminists should stand up against the gender critical perspective, whose *only* political goal is to tie women’s rights to an idealized biological norm. That is fascism. There is no other word for it. And the fact that the movement claims to speak as and for “women” is dangerous."

Navratilova initially responded by writing the following:

"Nothing idealized about being a biological woman. Just a fact. I am a feminist. But do go ahead and keep calling women like me fascists…name calling is all you got."

Lavery replied by urging Navratilova to re-consider her stance on the debate, saying:

"I don’t think you’re a fascist: I think attempts to normalize “sex-based rights”—which cannot *but* entail the surveillance and control of people’s bodies—are fascism. I encourage you—brilliant and unusual body!—to rethink."

In response, the Czech-American responded by re-iterating her demand for sex-based safe spaces, writing:

"Nobody here is trying to control bodies. Which in fact men had been controlling women bodies for millennia and still do… asking for sex based women’s spaces is not Fascism. Thank you."

As the long exchange headed towards an end, Lavery posted:

"Feeminists didn’t used to argue for “women’s spaces.” We want women in ALL spaces. It may be provisions need to be made for athletics. But the notion that women are so fragile they can’t use a bathroom that a man has ever been in… you’re Martina Navratilova!"

The back-and-forth continued for a short while longer, with Navratilova saying that "Men are physically stronger than women. That’s a fact," before going on to discuss gender-based violence, to which Lavery replied by saying that she thinks such violence is not dependent on biology, but is instead linked to "patriarchy, and I think it can and must be confronted."