Earlier this month, L'Equipe reported that several prominent top 20 players on both the ATP and WTA tours "co-signed and sent a letter to the four Grand Slam tournaments, demanding a substantial increase in their prize money".
"In essence, this letter calls for a greater distribution of profits generated by the four pillars of the tour to benefit the main stakeholders: the players, without whom the show would not take place," the report explained.
On the WTA side, Swiatek, Aryna Sabalenka, Coco Gauff, Jessica Pegula, Madison Keys, Jasmine Paolini, Mirra Andreeva, Zheng Qinwen, Paula Badosa and Emma Navarro all signed the letter, with Elena Rybakina the only current top 10 player missing.
ATP stars who signed the letter include Alcaraz, Novak Djokovic, Jannik Sinner, Alexander Zverev, Taylor Fritz, Casper Ruud, Jack Draper, Stefanos Tsitsipas, Alex de Minaur and Daniil Medvedev.
The letter was reportedly given the green light by both the WTA and ATP Players' Boards.
Swiatek was asked about her decision to sign the letter during a press conference at this week's Porsche Tennis Grand Prix in Stuttgart.
"Well, I think, like, there's some data available on the internet about the comparison between tennis and other sports," the five-time major winner said. "For sure, we've been discussing with Grand Slams about many topics.
"Yeah, I mean, it could be better, but I'm not going to say a lot because, first of all, we need to figure it out kind of internally. For sure, there's some time needed to do that. Yeah, I don't want to speak out right now about that."
In an interview with Marca, Alcaraz joined Swiatek in speaking about the topic for the first time.
"Tennis is a well-paid sport, but it can always be improved because there is a percentage that can be increased for the circuit and the players. Tennis is a well-paid sport, but the percentages have to be fair," the four-time Grand Slam titlist explained.
"If we put on a show so the fans can enjoy it and pay to see us, then the percentage has to be close to what we deserve. And that's why we've come together."
Alcaraz is in action at the ATP 500 tournament in Barcelona this week.