The European Super League (ESL) is a “disgraceful, self-serving” plan and a “spit in the face of football lovers”, says Uefa president Aleksander Ceferin.
He also said players who play for teams involved in the closed league would be “banned from the World Cup and Euros”.
Arsenal, Chelsea, Liverpool, Manchester City, Manchester United and Tottenham are among 12 clubs who have agreed to join the proposed ESL.
“We are all united against this nonsense of a project,” said Ceferin.
“I cannot stress more strongly how everyone is united against these disgraceful, self-serving proposals, fuelled by greed above all else,” he said.
“[It is a] cynical plan, completely against what football should be. We cannot and will not allow that to change.
“Players who will play in the teams that might play in the closed league will be banned from the World Cup and Euros. We urge everyone to stand tall with us as we do everything in our power to ensure this never ends up in fruition.
“This idea is a spit in the face of all football lovers. We will not allow them to take it away from us.”
The ESL will be a “new midweek competition” with teams continuing to “compete in their respective national leagues”.
After it was announced on Sunday, Fifa expressed its “disapproval” of the proposed competition and called on “all parties involved in heated discussions to engage in calm, constructive and balanced dialogue for the good of the game”.
World football’s governing body previously said it would not recognise such a competition and any players involved could be denied the chance to play at a World Cup.
On Monday, Ceferin reiterated clubs and players involved with the ESL could be banned “as soon as possible” from all Uefa competitions.
“We’re still assessing with our legal team but we will take all the sanctions that we can and we will inform you as soon we can,” he said.
“My opinion is that as soon as possible they have to be banned from all our competitions and the players from all our competitions.”
Ceferin was particularly critical of Manchester United executive vice-chairman Ed Woodward and Juventus chairman Andrea Agnelli, who have both stepped down from their roles at Uefa.
Agnelli was also a long-time president of the European Club Association (ECA), from which all 12 clubs involved in the ESL have resigned.
“He’s probably one of the biggest disappointments, or the biggest disappointment of all,” said Ceferin.
“I don’t want to be too personal. But the fact is that I’ve never seen a person that would lie so many times, so persistently that he did was unbelievable.
“I spoke with him also on Saturday afternoon. He said, ‘These are all only rumours. Don’t worry, nothing is going on’. And then he said, ‘I’ll call you in one hour’. And he turned off the phone.”
On Woodward, Ceferin added: “I didn’t have much contact with him but he called me last Thursday in the evening sayingthat he’s very satisfied with the [Champions League] reforms, that he fully supports the reforms, and that the only thing he would like to speak about is about financial fair play.
“And obviously he already signed something else.”
