UEFA have been backed by a key legal figure on their right to block new competitions including the collapsed European Super League - in a boost for Celtic and Rangers.

Advocate General Athanasios Rantos offered his opinion that UEFA and FIFA's right to block competitions is not in breach of EU law.

Organisers of the proposed Super League - which would see a number of elite clubs breakaway from European competitions including the Champions League - had claimed it was unfair for UEFA and FIFA to block the competition and threaten sanctions against clubs should they join the breakaway set-up.

However, the Advocate General has supported UEFA and FIFA and insisted sanctions can be made against clubs should they choose to join the European Super League.

Mr Rantos' opinion is not a legally binding verdict on the matter - with a final decision to be made next year - but signals that a Super League may not be feasible.

Clubs could join a breakaway European Super League but would then be unable to compete in domestic leagues or in the UEFA tournaments.

The news comes as a boost for Celtic and Rangers with the Champions League, Europa League and European Conference League supported in the latest development in the Super League saga.

A statement from the European Court of Justice in Luxembourg read: “While ESLC (European Super League Company) 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 organised by FIFA and UEFA without the prior authorisation of those federations.”

Mr Rantos commented: “The non-recognition by FIFA and UEFA of an essentially closed competition such as the ESL could be regarded as inherent in the pursuit of certain legitimate objectives, in that the purpose of that non-recognition is to maintain the principles of participation based on sporting results, equal opportunities and solidarity upon which the pyramid structure of European football is founded and to combat dual membership scenarios.”

A UEFA statement welcomed the update, adding: "EFA warmly welcomes today's unequivocal Opinion recommending a ruling of The Court of Justice of the European Union (CJEU) in support of our central mission to govern European football, protect the pyramid and develop the game across Europe.

"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 European Super League, 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."