Tennis greats Martina Navratilova and John McEnroe staged an on-court protest against Margaret Court over her homophobic outbursts and now face censure from Tennis Australia.

The two walked onto court for the legends doubles match at the Australian Open, carrying a banner emblazoned with "Evonne Goolagong Arena" in a plea for a name change because of Court's comments.

Their protest was in response to a ceremony honouring the 50th anniversary of Court's 1970 Grand Slam.

63-year-old Navratilova, who won 18 Grand slams during her career also posted a public letter on Tennis.com in which she blasted Court over her "hurtful" views towards the LGBTQA+ community.

The letter read: "When airports, buildings, streets or stadiums are named after particular people, it is done, or at least should be done, to honor exceptional human beings—our heroes.

"Think Muhammad Ali, Nelson Mandela, Martin Luther King, Billie Jean King, Rod Laver, Rosa Parks. Would it not be appropriate if the Staples Center were renamed as a tribute to Kobe Bryant? 

"Such luminaries excelled in their fields and transcended them; they made a positive contribution to mankind; they led by example. And, perhaps most of all, they were on the right side of history. 

"But Margaret Court does not belong in that company or category. Nobody disputes her achievements on the tennis court, and her place in the sport’s history remains as distinguished as it gets. Nobody wants to take away or diminish her career, least of all me. Margaret, Billie Jean and Rod were my childhood heroes. I wanted to be like them. 

"So, it pains me to say this, but Margaret Court Arena must be renamed. 

"As a worthy replacement, my vote goes to Evonne Goolagong. Evonne is the embodiment of what a role model or hero truly is. Her heritage, her success against the odds, her Hall of Fame career and her exemplary life off court, in which she has given so much of herself to so many causes, are all attributes we can celebrate wholeheartedly.

"In our tennis ‘family,’ we celebrate the good values of our sport and we love how democratic and inclusive it has become, the way it has driven out prejudice and unfair exclusion.

"Yes, we have free speech in a democracy, but that doesn’t mean that free speech doesn’t have consequences. When Margaret goes out of her way to single out a group of people and tell them they don’t deserve equal rights, that they are less than good parents, that they are not godly, that’s not merely free speech. It’s hateful and hurtful speech and it’s injurious to countless vulnerable people.

"Why not pick someone whom every child can look up to and want to emulate—a champion who inspires and motivates young and old to do their best and be their best every day?

"For me, that person is Evonne Goolagong. Evonne Goolagong Arena. Perfect."

The Czech tennis legend did not stop there when, following the game, she climbed into the umpire's chair and started to make a statement. However, the television feed was cut off within seconds.

McEnroe also slammed Court in a video posted on Monday in which he dubbed her the "crazy aunt" and pleaded with Serena Williams to beat her Grand Slam record.

“There’s only one thing longer than a list of Margaret Court’s tennis achievements — it’s her list of offensive and homophobic statements,” McEnroe said.

The pair are now facing punishment from Tennis Australia for what the governing body deemed as a breach of protocol.

In a statement released within hours of the on-court protest they said: "We embrace diversity, inclusion and the right for people to have a view, as well as their right to voice that view.

“But the Australian Open has regulations and protocols with respect to how any fan, player or guest can use our facility, the event and the global stage it provides. This is to ensure the integrity of our event.

“Two high-profile guests have breached these protocols and we are working through this with them,” they said.

There has not yet been any decision made on the punishment facing the two ex-tennis players.