The Spanish government has sent an email to the European Court of Justice to explain the legal reasoning behind its opposition to the European Super League, the Spanish ministry of culture and sport (CSD) told AFP on Tuesday.

The email expressed the government's position that "the improvement of competitions is possible through dialogue and always through the structures that already exist", said sources from the CSD.

"We have sent that opinion to the EU but also with the legal reasoning provided by the state," the sources added.

Real Madrid, Barcelona and Juventus remain attached to the project, even after the other nine teams, including Manchester United, Liverpool, Arsenal, Tottenham, Chelsea, Manchester City, Atletico Madrid, AC Milan and Inter Milan, all withdrew in April.

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UEFA initially opened disciplinary proceedings against the three remaining clubs but backed down last month after a commercial court in Madrid ruled any punishment would represent an infringement of European free trade laws.

The ruling has been referred to the European Court of Justice, with a decision expected this week on whether UEFA's power to punish clubs should be examined.

Real Madrid, Barcelona and Juventus are adamant the idea of a breakaway league is not dead, despite a huge backlash and protests from fans in England.

"There is a binding contract and no one can leave," said Madrid president Florentino Perez in June. "The Super League continues."

The botched proposal involved founding members enjoying guaranteed qualification to the league every year, playing fixtures against each other in midweek and splitting 3.5 billion euros between them for signing up.