Tennis is used to pay battles between the sexes when it comes to competitors' prize money, but that now looks set to spill over into the commentary box at Wimbledon.
Martina Navratilova has revealed that John McEnroe is paid, minimally, 10 times more than she is for the expert analysis the two provide during The Championships for the BBC.
The Czech-American legend told a wider BBC Panorama investigation on Sunday night — Britain's Equal Pay Scandal — of the disparity between what they receive for their services over the iconic fortnight. She has instructed her agent to ask for more money and relates her upset when discovering the different remuneration scales.
"Overall it was a shock because John McEnroe makes at least £150,000," said Navratilova, a long-time campaigner for equality in different areas of life. "I get about £15,000 for Wimbledon and unless John McEnroe's doing a whole bunch of stuff outside of Wimbledon, he's getting at least 10 times as much money."
Furthermore, Navratilova alleged she was told she was paid a comparable amount to men doing a similar job: "We were not told the truth, that's for sure. (I'm) not happy, needless to say. I mean it's shocking, it's still the good old boys' network. And you know the bottom line is that male voices are valued more than women's voices."
The programme estimates that McEnroe appeared about 30 times for the BBC at Wimbledon last year, compared to his female counterpart's 10 appearances.
BBC Sport told Panorama: "John and Martina perform different roles in the team, and John's role is of a different scale, scope and time commitment. They are simply not comparable. John's pay reflects all of this. Gender isn't a factor.
"Martina is one of a number of occasional contributors who is contracted to carry out a fixed volume of work and paid per appearance. The BBC believes her pay reflects what she is asked to do. Along with Sue Barker, John is regarded as the face of our Wimbledon coverage. He is a defining voice within the BBC's coverage."
Gender politics are rarely far below the surface in tennis, with Andy Murray establishing himself as a powerful voice from the men's side of the game arguing for equality.
Wimbledon put the prize money argument to bed in 2007 when it became the last of the four Grand Slams to introduce full parity. That does not extend to all levels further down the game and it remains a sensitive subject.
McEnroe became directly involved in the issue just before Wimbledon last year when he was asked about claims that Serena Williams could be described as the greatest tennis player of all time.
While acknowledging her greatness as the best female ever, he refused to go along with such a straightforward analysis. "If she had to just play the circuit — the men's circuit — that would be an entirely different story," he said, speculating that "she'd be like 700 in the world".
Williams was unimpressed, asking amid the ensuing storm that he "please keep me out of your statements that are not factually based". Blessed with an extremely sharp mind and wry sense of humour, it is McEnroe's capacity for original thought and provocative analysis that have made him the star of the BBC team since he started appearing in the late Nineties.
He works a very busy schedule during the major tennis events as he is also in huge demand from the big American and international broadcasters, often ducking from one studio to another for his various stints.
McEnroe could therefore cite that there is very much a market rate for his services.
In terms of the BBC, his clearest parallel would be with Michael Johnson. Athletics is another sport that the Beeb still covers extensively with comparable levels of interest between men's and women's events, and Johnson has also proved himself to be a peerless analyst who can reach out to an audience well beyond the hardcore fan.
While Navratilova can definitely boast a superior playing record by any measure — 18 Grand Slam titles to McEnroe's seven, for example — few would consider her to be an equal draw as a broadcaster.
The parity issue in tennis is not one that is likely to go away. As The Daily Mail revealed just before the recent Australian Open, Novak Djokovic has become a strident voice in declaring that the men should be fighting harder to secure themselves better levels of pay and more sympathetic scheduling.
© Daily Mail