The European Court of Justice (ECJ) Advocate General Athanasios Rantos has rejected the European Super League's (ESL) claim that FIFA and UEFA operated an unfair monopoly under European Union (EU) competition law, the court said in a statement on Thursday.

"The FIFA-UEFA rules under which any new competition is subject to prior approval are compatible with EU competition law," Rantos said in the statement.

Back in April 2021, 12 European top clubs announced the launch of a breakaway league, the ESL. The plans fell apart in the face of strong opposition from FIFA, UEFA and individual football associations. Nine of the participating teams soon quit the project, leaving only Barcelona and Real Madrid of La Liga and Juventus of Serie A behind the ESL.

The three clubs took legal action in response, arguing that the governance of FIFA and UEFA was incompatible with EU competition law. Though the ECJ's final ruling won't come until early 2023, the advocate general disagreed with Real, Barca or Juventus over the ESL scheme.

"Whilst ESLC is free to set up its own independent football competition outside the UEFA and FIFA ecosystem, it cannot however, in parallel with the creation of such a competition, continue to participate in the football competitions organized by FIFA and UEFA without the prior authorization of those federations," Rantos added.

"FIFA welcomes the opinion issued today by Advocate General Rantos of the European Court of Justice in which he confirms the standing and legitimacy of FIFA and UEFA to approve any new football competitions. By the same token, the Advocate General considers that sanctions may be imposed in respect of competitions which do not satisfy the approved authorization criteria," FIFA said in a statement.

"UEFA warmly welcomes today's unequivocal opinion recommending a ruling of the CJEU in support of our central mission to govern European football, protect the pyramid and develop the game across Europe," UEFA said in their own statement.

Moreover, the European Club Association and Premier League both expressed their support for Rantos' statement.

"The opinion of the Advocate General is one step in an ongoing case, and we are pleased with the recognition of the right of third parties to organize pan-European club competitions. The advocate general made clear that UEFA has a monopolistic position which comes with important responsibilities for enabling third parties to act freely in the market," ESL-supporting company A22 Sports Managing CEO Bernd Reichart said.

"However, we believe the 15 judges of the Grand Chamber who are entrusted with the responsibility to examine this case, will go substantially further and provide the opportunity for clubs to manage their own destiny in Europe," he added.