Manchester United and Manchester City face the threat of losing billions of pounds if they quit the European Super League.
An agreement was struck at the weekend for 12 teams - including United, City, Chelsea, Liverpool, Arsenal and Tottenham Hotspur - to become founder members of the breakaway league.
Supporters of all clubs across Europe have reacted furiously to the news and people are rallying to ensure it’s stopped in its tracks.
There are said to be doubts creeping in amongst senior figures at some of the rebel clubs and City boss Pep Guardiola has admitted his opposition to the idea.
"It is not a sport if success is guaranteed or if it doesn’t matter when you lose," Guardiola said at his press conference on Tuesday.
"I have said many times I want a successful Premier League, not just one team at the top."
However, Real Madrid president Florentino Perez - who has been appointed Super League chief - insists the 12 clubs involved have made a commitment.
"The contract of the Super League is binding. Nobody can leave, we will work all together," he told El Chringuito on Monday night. "All the clubs signed the contracts last Saturday - there's no problem."
The Telegraph adds that any club which pulls out without the consent of its fellow members would leave itself open to legal action, particularly if it led to the collapse of the multi-billion pound competition.
The rebels are also facing up to the prospect of legal action from the Premier League after the 14 other clubs attended an emergency meeting chaired by chief executive Richard Masters today.
Meanwhile, UEFA have revealed plans to ban players attached to Super League clubs from competing for their national teams. The Super League have already started to challenge this 'in the relevant courts'.
Mark Orth, an expert in sports competition law, has told the Daily Mail that the 'Big Six' would be in a strong position if any court battle with UEFA was needed.
"I am of the opinion they have a strong case," said Orth.
"The court is the right way to go. They have a good chance of winning. There are good prospects for the start of the Super League and the clubs that take part."
