Europe's top clubs have said they will boycott FIFA's proposed new Club World Cup in a major blow to Gianni Infantino's plans to revamp the competition.
The FIFA president had hoped to get backing for a "pilot" edition of the new 24-team tournament in 2021 alongside a new worldwide Nations League for national teams.
But he has been forced to drop the Nations League plan before Friday's meeting of the FIFA Council in Miami, after his own task force said there is no space for such a tournament in the international calendar.
And now a letter to UEFA and Infantino from the European Club Association (ECA) head Andrea Agnelli, chairman of Italian side Juventus, has emerged, delivering another blow to his proposals to transform the game.
The letter, published in German newspaper Suddeutsche Zeitung, is signed by 15 members of the ECA board including officials from Barcelona, Manchester United and Ajax.
They said they are "firmly against any approval of a revised Club World Cup at this point in time and confirm that no ECA clubs would take part to such a competition".
Nevertheless, Infantino announced at Friday's FIFA Council meeting that he's moving ahead with his plans anyway before sidestepping questions about the boycott.
The ECA represents all Europe's leading teams who would be expected to feature in a revised Club World Cup.
A spokesperson for the organisation declined to comment on the content of the letter but told Reuters that they would be meeting later this month to discuss the situation.
"We are following developments around the FIFA Council closely. Any decision impacting our members will be discussed and assessed in detail at our upcoming board meeting to be held on March 26," they said.
Infantino is expected to hold a news conference following the council meeting on Friday.
UEFA, European football's governing body, is unlikely to fight Infantino's plans with the proposal expected to be passed on to a further meeting ahead of June's congress.
The FIFA Council is also expected to decide to continue exploring plans to expand the 2022 World Cup in Qatar to 48 teams with the possibility of additional hosting in other countries.
Information from Reuters contributed to this report.