The fight to stop the creation of a European Super League has received a lot of support.
The rules of football's European and world governing bodies are compatible with EU competition law according to a report by the European Court of Justice.
After a court case, Athanasios Rantos gave his observations.
The Grand Chamber will make a final ruling in the spring.
It had been claimed that Uefa and Fifa were breaking competition law by threatening to punish clubs and players who joined a league outside of Europe.
When the plans for a European Super League were announced, there was a lot of uproar.
The backlash from fans, football governing bodies and even the government caused the sixPL sides to withdraw their support.
The Super League idea is still being pushed by Real Madrid and Barcelona.
In a statement on Thursday, European football's governing body Uefa said it "warmly welcomed" the observations from Rantos which it said supported "our central mission to govern European football, protect the pyramid and develop the game across Europe"
The European football pyramid has a dynamic and democratic governance structure.
It supports the central role of federations in protecting the sport, upholds fundamental principles of sporting merit and open access, as well as unifying football with shared responsibility and solidarity.
Football in Europe is opposed to any proposals that would threaten the entire European sports industry.
The final decision by the court's Grand Chamber will be influenced by the report, but it is not binding.
Any new competition that is subject to prior approval is compatible with EU competition law.
ESLC is free to set up its own independent football competition, but it can't participate in the football tournaments organised by Uefa and Fifa without the prior permission of those federations.
The Super League clubs were fined by Uefa. Following the legal process, action against the other three was stopped.
According to a statement from the European Clubs Association, "Rantos proposes a clear rejection of the efforts of a few to undermine the foundations and historical heritage of European football for the many."
As the body representing nearly 250 of Europe's top football clubs, ECA is explicit in its strong opposition towards those self-interested few who want to disrupt European club football and undermine the values that underpin it.