UEFA has warned it will boycott all FIFA competitions if FIFA President Gianni Infantino proceeds with plans to sell ownership stakes in the World Cup and other major tournaments to private investors.
The decision was reached unanimously by UEFA's 55 member associations during an emergency meeting on Thursday.
If implemented, the boycott would cover the men's and women's World Cups as well as the Club World Cup, with the 2027 Women's World Cup likely to be the first tournament affected.
In a strongly worded statement, UEFA said it "unanimously and unequivocally" rejected FIFA's proposal to transfer ownership interests in the World Cup and other FIFA competitions to private investors.
The European governing body argued that the World Cup is a global sporting legacy built over generations and stressed that "the World Cup is not for sale."
"The World Cup cannot be treated as an investment product. It is one of football's greatest sporting legacies. It has been built over generations by players, national teams and supporters across every continent. No part of it should ever be surrendered to private investors. The World Cup is not for sale," UEFA said.
"It is both irresponsible and indefensible that a proposal of such significance for football was conceived in secret and brought to the brink of approval without any meaningful consultation with those entrusted with stewarding the game. This is not merely a profound failure of leadership, but an abdication of FIFA's duty as the custodian of world football."
UEFA further warned that private investment would place commercial returns ahead of the interests of players, fans and national associations.
"This model has no place in world football. Football's future cannot be dictated by the expectations of those whose first duty is to maximise financial return. Nor can the interests of national associations, leagues, clubs, players and supporters become subordinate to investor returns. Football cannot mortgage its future for financial gain," it said.
The organisation said no UEFA national team would participate in FIFA competitions unless the proposal is completely abandoned and FIFA guarantees it will not pursue private ownership of its tournaments in the future.