The opinion of Advocate General Athanasios Rantos is not binding on the court, which is examining a complaint from the firm that planned to start the new league, but it will be influential and taken as a sign of the direction the case is taking."EU competition rules do 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 wrote.The court's final decision on the complaint is not expected until early next year, but the decision will be a relief for the world's biggest football associations and the existing national European leagues wary of allowing some of their richest clubs to break away.The legal opinion was immediately welcomed by lobby groups representing European football clubs, leagues and supporters.Fan association Football Supporters Europe said: "Last year, twelve obscenely wealthy clubs tried to destroy European football by creating a closed breakaway league."They failed because fans across the continent — including their own —stood in solidarity against their plans."And the European Club Association hailed Rantos' advice as "a clear rejection of the efforts of a few to undermine the foundations and historical heritage of European football for the many."The attempt to set up an elite trans-European league in 2021, under the aegis of the European Super League Company (ESLC), initially attracted the support of some of the continent's biggest and richest clubs -- but triggered a backlash from fans and several governments.The effort fell apart within a frantic 48 hours that threatened to see the European game implode, but left behind