European soccer's governing body UEFA has warned clubs linked to a breakaway Super League that they face being banned from domestic and international competitions if they set up a rival to the Champions League.
In a joint statement with Spanish, English and Italian leagues and federations, UEFA said it will consider "all measures", including the courts and bans from domestic leagues, in opposition to plans for a breakaway competition.
UEFA said it had learnt that clubs from those countries "may be planning to announce their creation of a closed, so-called Super League".
"If this were to happen, we wish to reiterate that we....(and) also FIFA and all our member associations - will remain united in our efforts to stop this cynical project, a project that is founded on the self-interest of a few clubs at a time when society needs solidarity more than ever," UEFA said.
"We will consider all measures available to us, at all levels, both judicial and sporting in order to prevent this happening. Football is based on open competitions and sporting merit; it cannot be any other way," the statement added.
In January, FIFA had said that a breakaway league would not be recognised and that "any club or player involved in such a competition would as a consequence not be allowed to participate in any competition organised by FIFA or their respective confederation" - meaning players would be banned from the World Cup.
Sunday's UEFA statement said: "The clubs concerned will be banned from playing in any other competition at domestic, European or world level, and their players could be denied the opportunity to represent their national teams.
"We thank those clubs in other countries, especially the French and German clubs, who have refused to sign up to this. We call on all lovers of football, supporters and politicians, to join us in fighting against such a project if it were to be announced. This persistent self-interest of a few has been going on for too long. Enough is enough."