The PTPA, an independent players' union co-founded by Novak Djokovic and Vasek Pospisil in 2019 and supported by Australian star Nick Kyrgios, said after years of good-faith efforts to reform professional tennis, it has been forced to take legal action to end "monopolistic control" of the sport.

In its sights are the men's and women's governing bodies, the International Tennis Federation (ITF), which runs team competitions, and the International Tennis Integrity Agency, which oversees the sport's anti-doping and anti-corruption system.

Twelve current and former players, including Djokovic, Pospisil and Kyrgios, are listed as plaintiffs along with the PTPA.

"Today, the PTPA, alongside over a dozen professional tennis players and on behalf of the entire player population, and renowned international law firm and historical player advocates Weil, Gotshal & Manges LLP, initiated a series of legal actions in the US, UK and EU against the sport's governing bodies," the association said in a statement.

"The lawsuits expose systemic abuse, anti-competitive practices, and a blatant disregard for player welfare that have persisted for decades."

Among the PTPA's complaints are the suppression of competition between tournaments, which it says reduces prize money, an archaic ranking points system, an unsustainable schedule and financial exploitation.

It also accused the governing bodies of disregarding player welfare by forcing athletes to compete late at night and in extreme heat, while the PTPA branded anti-doping practices an invasion of privacy.

In response the ATP accused the PTPA of choosing "division and distraction" and having no meaningful role in the sport.

"We strongly reject the premise of the PTPA's claims, believe the case to be entirely without merit, and will vigorously defend our position," an ATP statement read.

"ATP remains committed to working in the best interests of the game -- towards continued growth, financial stability, and the best possible future for players, tournaments, and fans."

Pospisil, a former Wimbledon doubles champion, said the action was not just about money but fairness, safety, and basic human dignity

"I'm one of the more fortunate players and I've still had to sleep in my car when travelling to matches early on in my career," he said.

"Imagine an NFL player being told that he had to sleep in his car at an away game? It's absurd and would never happen, obviously. No other major sport treats its athletes this way.

"The governing bodies force us into unfair contracts, impose inhumane schedules, and punish us for speaking out. The legal actions taken today are about fixing tennis for today's players and future generations."