World leagues and player unions are threatening to take legal action if FIFA does not reschedule the 2025 Club World Cup.

A letter to FIFA president Gianni Infantino, says the sport's schedule is now "beyond saturation".

It says calendar changes such as the addition of the new 32-team Club World Cup – currently scheduled to take place in June and July 2025 – have created "economic harm" to domestic leagues and have pushed players "beyond their limits".

It calls on FIFA Council to reschedule the Club World Cup and to reopen discussions on the international calendar for the period up to 2030.

"Should FIFA refuse to formally commit to resolving the issues, as set out above, at its upcoming council, we shall be compelled to advise our members on the options available to them, both individually and collectively, to proactively safeguard their interests," the letter states.

"These options include legal action against FIFA, on which we have now commissioned external expert advice."

The letter has been sent by the World Leagues Association and world players' union FIFPRO, which respectively count the Premier League and the Professional Footballers' Association among their members.