New expanded club World Championship is a threat to players' health.
This is the view of the International Players' Union (Fifpro), which now wants to take the International Football Association (Fifa) to court.
The players' unions in England and France have filed a lawsuit against Fifa.
"Players and unions have consistently pointed out that the current football calendar is overloaded and unsustainable", says Fifpro Europe in a statement.
The Club World Championship is to be played in the USA in the summer of 2025 with 32 teams. Previously, there were seven teams and the tournament was decided in December.
Fifa believes that players get sufficient recovery time since the month-long tournament takes place when many major leagues are on break.
"With all preparations and travel included, the tournament is likely to create up to six weeks of extra work in an already packed schedule", says Fifpro.
For many of the world's best players, this means major tournaments three summers in a row: the European Championship/South American Championship this year, the Club World Championship in 2025, and the World Championship in 2026.
