The European Super League (ESL) is on "standby" despite nine of the 12 founding teams withdrawing, says Real Madrid president Florentino Perez.
After a furious backlash against the proposed tournament that was announced on Sunday, all six Premier League clubs involved withdrew on Tuesday.
Spanish club Atletico Madrid and Italian sides AC Milan and Inter Milan have also formally pulled out.
"We're going to continue working," said Perez. "The project is on standby."
Real Madrid, Barcelona and Juventus have not withdrawn, although Juventus chairman Andrea Agnelli said the project could not now proceed.
Speaking on the El Larguero show on Spanish radio station Cadena Ser, Super League chairman Perez claimed all 12 clubs "have not left yet".
"You cannot get out of the contract like this - they are binding contracts," he added.
When asked what the penalty was for leaving the project, Perez did not answer.
Perez reiterated his view that the ESL was created "to save football", having also previously said the move had been made because young people were "no longer interested in football" because of "a lot of poor quality games".
He added he was "sad and disappointed" by the reaction to the project, which the clubs have been working on "for around three years".
He accused Uefa president Aleksander Ceferin and various countries' footballing authorities of "aggression" and "threats" towards the ESL.
"Maybe we didn't explain it well, but they also didn't give us an opportunity to explain it," said the 74-year-old.
"I've been in football for 20 years and I've never seen threats like this. It was like we killed someone. It was like we killed football. But we were trying to work out how to save football."
A revamped 36-team Champions League, starting in 2024, was agreed on Monday, although the ESL teams had said in its announcement of Sunday it did not think Uefa's reforms went far enough.
"The Champions League format is old and only interesting from the quarter-finals onwards," said Perez.
"This format clearly doesn't work, so we thought that we could have a format where the most important teams in Europe play against each other from the very beginning of the season.
"We worked out the numbers and felt we could make much more money, more money for all the other teams too."
Perez also claimed one of English football's 'big six' - Arsenal, Chelsea, Liverpool, Manchester City, Manchester United and Tottenham - were reluctant about the ESL from the start.
"There was someone in the English group that didn't have much interest, I won't say who," he said.
"That began to infect others, who are also people of an age, and who are perhaps afraid because they did not understand anything of what was happening.
"We all signed a binding agreement, but I think one was never very convinced."