“We cannot accept that these are just plans and proposals for an open discussion with stakeholders about the future of professional football,” Tebas told The Times. “In reality, we were presented with a concrete project developed by UEFA in full cooperation with a small group of rich and powerful European clubs to reform European club competitions after 2024 in a format that could destroy domestic competitions and the sporting and financial sustainability of the vast majority of clubs in Europe.

“We are open for a constructive dialogue to reform European football together with other stakeholders, but if this is the project on the table, then the margins for negotiations are very limited.”

While the Champions League’s main competition will continue to be the 32-team event it is today, UEFA envisages substantial changes to its format to ensure a longer group stage in which teams would play in four groups of eight, with the top four teams qualifying for the knockout stages. Such a setup would create dozens more matchups of elite clubs to sell to broadcasters, with some perhaps on weekend dates that are traditionally reserved for domestic league play.

Champions from lower-profile leagues like those in the Netherlands, Belgium, Portugal and most of Eastern Europe, as well as elite-league clubs outside the top four or five spots in their domestic competitions, would be relegated to a 32-team second-tier competition and to a third division with 64 teams. Teams would be eligible to be promoted and relegated among the three divisions, but the financial resources available to those at the top could create a competitive advantage that might secure their places in the Champions League for the foreseeable future. Only four of the 32 places would be reserved for incoming clubs each season.

Leaders of Europe’s domestic leagues fear the changes could reduce their competitions to fourth-tier afterthoughts behind the three European competitions, while small and medium-size clubs have expressed concern that their fans would no longer have the chance to dream of even competing against the continent’s biggest clubs for Europe’s biggest prizes.

“The objective of football is to give happiness to fans, and to give happiness is to have a chance of winning,” said Bernard Caiazzo, the owner of the French team St.-Étienne.

The uncertainty has already prevented some teams from securing outside investment, according to Caiazzo. His club, once a power in European competition, had been in talks with minority investors who have now cooled on buying a minority stake, he said.