The Super League's claim that UEFA's governance of European football constitutes an illegal monopoly under EU competition law has been rejected by the European Court of Justice's Advocate General.

The non-binding opinion from Advocate General Athanasios Rantos was published on Thursday ahead of the court's final ruling on the matter, which is expected early next year.

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The Super League filed a lawsuit with a Madrid court in April 2021 when the breakaway competition was launched, seeking protection from expected UEFA sanctions aimed at the clubs involved.

The Spanish judge granted a preliminary injunction, leading UEFA to suspend disciplinary proceedings -- although that injunction was lifted a year later -- before referring the case to the European Court of Justice.

In his opinion, Advocate General Rantos said that "the FIFA-UEFA rules under which any new competition is subject to prior approval are compatible with EU competition law."

"Having regard to the competition's characteristics, the restrictive effects arising from the scheme are inherent in, and proportionate for achieving, the legitimate objectives related to the specific nature of sport that are pursued by UEFA and FIFA," he said.

The Advocate General argued that EU competition law "did not prohibit FIFA, UEFA, their member federations or their national leagues from issuing threats of sanctions against clubs affiliated to those federations when those clubs participate in a project to set up a new competition."

He found that while the European Super League Company was free to set up its own competition outside of UEFA and FIFA, it could not continue to take part in UEFA and FIFA competitions at the same time, without their authorisation.

UEFA released a statement in response to the ruling on Thursday which read: "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 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 (@UEFA) December 15, 2022

"UEFA welcomes today's unequivocal Opinion of Advocate General Rantos, which is an encouraging step towards preserving the existing dynamic and democratic governance structure of the European football pyramid.

"The Opinion reinforces the central role of federations in protecting the sport, upholding fundamental principles of sporting merit and open access across our members, as well as uniting football with shared responsibility and solidarity.

"Football in Europe remains united and steadfastly opposed to the ESL, or any such breakaway proposals, which would threaten the entire European sports ecosystem.

"While we await the Court's final judgment due next year, UEFA, as a public interest, not-for-profit governing body, will continue to be fully focused on its mission to develop football for all, in close cooperation with national associations, leagues, clubs, players, fans, EU institutions, governments and other relevant stakeholders who have the true values of football at heart."

In effect, the Super League clubs would have to break away entirely from the existing football ecosystem if they wished to pursue the project.

LaLiga also released a statement which read: "LaLiga welcomes the conclusion of the Advocate General that the FIFA and UEFA rules which make any new competition subject to their authorization are compatible with EU law.

"LaLiga trusts that the court judges will share the opinion of the Advocate General when they publish their final verdict in the coming months."

The announcement of a breakaway Super League involving 12 of Europe's top clubs -- Real Madrid, Barcelona, Juventus, Manchester United, Liverpool, Manchester City, Chelsea, Arsenal, Tottenham Hotspur, AC Milan, Inter Milan and Atletico Madrid -- and intended to replace the UEFA Champions League sent shockwaves through the football world when it came on April 18, 2021.

Nine of the clubs were forced to publicly disown the project within days after pressure from fans, politicians and football's governing bodies, but the remaining three -- Real Madrid, Barcelona and Juventus -- have maintained their support for the scheme.

In October this year the company behind the Super League, A22 Sports Management, appointed a new chief executive, Bernd Reichart, who began efforts to relaunch and rehabilitate the competition's image.