Uefa, the Premier League and UK Prime Minister Boris Johnson have condemned 12 major European clubs, including the ‘big six’ from England, signing up to a breakaway European Super League.
Arsenal, Chelsea, Liverpool, Manchester City, Manchester United and Tottenham are part of the group.
La Liga’s Atletico Madrid, Barcelona and Real Madrid and Serie A’s AC Milan, Inter Milan and Juventus are involved.
Uefa said it will use “all measures” possible to stop the “cynical project”.
Senior figures at European football’s governing body are furious about the proposals.
Johnson said the plans would be “very damaging for football” and that the UK government supports the sport’s authorities “in taking action”.
He added: “The clubs involved must answer to their fans and the wider footballing community before taking any further steps.”
The European Clubs’ Association (ECA), which represents Europe’s clubs, held an emergency meeting on Sunday in the wake of the reports.
BBC Sport understands none of the clubs mentioned in the Super League reports responded to a request to attend the meeting.
The meeting was chaired by Ajax chief executive Edwin van der Sar. Bayern Munich and Paris St-Germain were among the clubs who were present.
In a statement the ECA said it would be “strongly opposed” to a “closed super league model”.