The three remaining European Super League rebels stepped up their criticism of UEFA on Saturday, with Barcelona, Real Madrid and Juventus denouncing intolerable threats for their refusal to back down on the prospect of a breakaway competition.

The other nine clubs who formed the ill-fated Super League three weeks ago accepted a settlement on Friday to be fined by UEFA and stay within the open Champions League structure.

"We regret to see that our friends and founding partners of the Super League project have now found themselves in such inconsistent and contradictory position when signing a number of commitments to UEFA yesterday," Barcelona, Madrid and Juventus said in a joint statement.

"We have the duty to act in a responsible manner and persevere in the pursuit of adequate solutions, despite the unacceptable and ongoing pressures and threats received from UEFA."

The trio risks being banned from the Champions League as UEFA pursues a disciplinary process against them for not disavowing the Super League and being reintegrated into the existing system.

"The founding clubs have suffered, and continue to suffer, unacceptable third-party pressures, threats, and offenses to abandon the project and therefore desist from their right and duty to provide solutions to the football ecosystem via concrete proposals and constructive dialogue," Barcelona, Madrid and Juventus said. "This is intolerable under the rule of law."

The Super League project imploded after the English clubs — Arsenal, Chelsea, Liverpool, Manchester United, Manchester City and Tottenham — backed out inside 48 hours last month after a backlash from the fans and British government. The Premier League clubs along with Atletico Madrid, AC Milan and Inter Milan have officially signed up to a settlement with UEFA to participate only in the existing open European competitions and accepted giving up 5% of revenue for one season playing in Europe.

"We are fully aware of the diversity of reactions to the Super League initiative and, consequently, of the need to reflect on the reasons for some of them," the remaining Super League clubs said. "We are ready to reconsider the proposed approach, as necessary. However, we would be highly irresponsible if, being aware of the needs and systemic crisis in the football sector, which led us to announce the Super League, we abandoned such mission to provide effective and sustainable answers to the existential questions that threaten the football industry."