The tennis players' association co-founded by Novak Djokovic has sued the main groups that run the sport in a bid to gain ...

The PTPA called the women's and men's tours, the ITF and the ITIA a "cartel, while the four major events—Wimbledon, US Open, French Open and Australian Open—were classed as "co-conspirators".

The group said it met with more than 250 players—women and men, and a majority of the top 20 in the WTA and ATP rankings—before going to court.