Novak Djokovic, Jannik Sinner, Aryna Sabalenka and Coco Gauff are among 20 leading tennis players who signed a letter sent to the heads of the four Grand Slam tournaments seeking more prize money and a greater say in what they called “decisions that directly impact us.”

The letter, a copy of which was obtained Thursday by The Associated Press, is dated March 21 and begins with a request for an in-person meeting at this month’s Madrid Open between representatives of the players and the four people to whom it was addressed: Craig Tiley of the Australian Open, Stephane Morel of the French Open, Sally Bolton of Wimbledon and Lew Sherr of the U.S. Open.

At the bottom of the message are the handwritten signatures of 10 of the top 11 women in the rankings from the week of March 3 – Elena Rybakina‘s name is missing – and the full list of the top 10 men that week.

The women are the No. 1-ranked Sabalenka, Gauff, Iga Swiatek, Jessica Pegula, Madison Keys, Jasmine Paolini, Emma Navarro, Zheng Qinwen, Paula Badosa and Mirra Andreeva. The men are the No. 1-ranked Sinner – who is currently serving a three-month doping ban – 24-time major champion Djokovic, Alexander Zverev, Carlos Alcaraz, Taylor Fritz, Casper Ruud, Daniil Medvedev, Andrey Rublev, Stefanos Tsitsipas and Alex de Minaur.

Of the 20, 15 have won at least one Grand Slam title or reached a major final.

The players outline three areas they want to focus on:

– Grand Slam tournaments should make financial contributions to player welfare programs funded by the two pro tours.

– Prize money should increase “to a more appropriate percentage of tournament revenues, reflective of the players’ contribution to tournament value.”

– The athletes should have more say in decisions “directly impacting competition, as well as player health and welfare.”

News of the letter – which was first mentioned by French sports newspaper L’Equipe – arrives about two weeks after the players’ association co-founded by Djokovic filed an antitrust lawsuit against the women’s and men’s professional tours, the International Tennis Federation and the sport’s integrity agency in federal court in New York. Djokovic was not listed as one of the plaintiffs, because he said he wanted to see other players step up.

That suit seeks more money for players, saying too little of the revenues end up in the athletes’ hands, and lays out a series of other complaints about the way the sport is run.

The antitrust filing last month included a reference to a report “that the U.S. Open generated more revenue from the sale of one specialty cocktail ($12.8 million) than it paid to the men’s and women’s champions combined.”

The U.S. Tennis Association offered a record total of $75 million in total compensation – which includes prize money and payouts to cover players’ expenses – for its Grand Slam tournament in 2024. That represented an increase of about 15% from the $65 million offered in 2023 at the U.S. Open.

Based on currency exchange figures at the times of the events, Wimbledon had about $64 million in prizes last year, with the French Open and Australian Open both at about $58 million.

“The USTA is always available for and welcomes open and direct conversations with players, whether on site at the U.S. Open or at any other point of the year, as we are consistently looking for ways to enhance our event for the benefit of players and fans,” spokesman Brendan McIntyre said in a written statement.

“The USTA is incredibly proud of the U.S. Open’s leadership in player compensation throughout its history and our support to grow professional tennis not only in the United States but worldwide,” he wrote. “This includes offering equal prize money to men and women for more than 50 years and awarding the largest purse in tennis history at the 2024 U.S. Open.”

The next Grand Slam tournament is the French Open, with main-draw matches starting in Paris on May 25.