FIFA said clubs must release players by December 27.

The tournament is due to start 13 days later, on January 9.

The WLF, which represents more than 40 professional leagues worldwide including Europe's top five divisions, said that date was "unreasonable and disproportionate" and that it had not received a reply when it contacted FIFA and the Confederation of African Football (CAF) twice last month.

"As indicated in our unanswered letter of November 19, more than a month ago, we consider that the FIFA rule must be adapted," WLF general secretary Jerome Perlemuter wrote, as reported by Reuters.

"As a consequence, in order to mitigate the impact of the decisions made on the AFCON, we consider that the release of players shall start on January 3 for those clubs and players having matches before then.

"We will also consider that any sanction imposed by FIFA will be deemed abusive, null and void."

The AFCON is set to take place in Cameroon from January 9 to February 6.

It was originally scheduled to take place in June and July 2021 but it was switched back to its usual slot in January and February at Cameroon's request to avoid poor playing conditions due to it being the country's wet season.

WLF claimed the tournament was going "against CAF's initial commitment made in 2017 to play the finals in June and July".

"Our clubs gladly commit to this solidarity scheme," said Perlemuter, as reported by Reuters.

"But in consideration, we expect decisions not to be made in isolation by FIFA and CAF.

"We urge for more dialogue and cooperation in matters relating to the match calendar."