World governing body Fifa is facing the threat of legal action from world players’ union Fifpro and the World Leagues Association – which includes the Premier League – if it continues with plans to host a 32-team Club World Cup at the end of next season.

They say the global football calendar is “now beyond saturation, to the point that national leagues are unable to properly organise their competitions” while “players are being pushed beyond their limits, with significant injury risks and impacts on their welfare”.

BBC Sport reported in December that the PFA was taking legal advice over the lack of consultation over an increasingly congested calendar and the impact that was likely to have on its members.

PFA chief executive Maheta Molango has been part of a series of high-level discussions over the intervening period, including the European Leagues general assembly last month, when Premier League chief executive Richard Masters said the calendar was ‘at tipping point’.

Next season, all three European club competitions will be expanded to 36 teams. The Champions League and Europa League will have eight first phase games compared to the current six. It is possible a club would have to play 17 matches to win either competition.

Manchester City and Chelsea are among the 12 European representatives at the expanded Club World Cup, to be held in the United States in June and July next year.

In a letter addressed to Fifa president Gianni Infantino and general secretary Mattias Grafstrom, seen by BBC Sport, Fifpro and the World Leagues Association say if Fifa extends its own competitions then it should alter others.

It adds that “imposing the burden of adaptation on national leagues and players is inherently abusive” and is “jeopardising national leagues and affecting the health and wellbeing of players”.

However, BBC Sport understands Fifa believes it has taken into account player welfare with their scheduling programme.