FIFA has threatened to ban players from its competitions, including the World Cup, if they compete in a breakaway European Super League.
The world football governing body and all six of football's continental confederations issued a statement Thursday to reiterate that the proposed tournament, which would effectively replace the Champions League, would not be recognized or receive approval.
"In light of recent media speculation about the creation of a closed European 'Super League' by some European clubs, FIFA and the six confederations (AFC, CAF, Concacaf, CONMEBOL, OFC, and UEFA) once again would like to reiterate and strongly emphasize that such a competition would not be recognized by either FIFA or the respective confederation(s)," the statement read.
"Any club or player involved in such a competition would, as a consequence, not be allowed to participate in any competition organized by FIFA or their respective confederation."
Reports emerged in October suggesting that Wall Street bank JP Morgan, Liverpool, and Manchester United, as well as other wealthy clubs from England, France, Germany, Italy, and Spain, were in talks about forming a new 18-team competition.
Outgoing Barcelona president Josep Maria Bartomeu announced in late October that the five-time Champions League winners had accepted an invitation to play in the league, which would be named the "European Premier League."
After Bartomeu's bombshell, UEFA reiterated its strong opposition to a European Super League, saying: "The principles of solidarity, promotion, relegation, and of open leagues are non-negotiable."