Top European clubs have told Fifa they would boycott the revised Club World Cup which is scheduled for 2021, reports BBC Sport.

The European Club Association (ECA) says any new competitions should be part of an agreed framework for the international match calendar post-2024.

ECA board members, including Manchester United's chief executive Ed Woodward, signed a letter expressing concerns.

"[We are] firmly against any potential approval of a revised CWC - no ECA clubs would take part," it said.

The Club World Cup is currently held every December and features seven teams from six confederations.

The revised competition would involve 24 teams - including eight from Europe - and take place from June to July.

The ECA's letter was addressed to Uefa president Aleksander Ceferin who has been asked to act as its representative at the Fifa Council meeting, which is taking place in Miami.

Fifa said it was aware of concerns of "serious interference with critical matches" but added that members of its own task force "felt that it was feasible to play the Club World Cup" during that period.