Manchester City manager Pep Guardiola said a European Super League in which 15 clubs cannot be relegated was not sport and has called on those behind the project to explain themselves.
City, along with Manchester United, Liverpool, Chelsea, Arsenal and Tottenham Hotspur, are the six Premier League clubs signed up for the new 20-club league announced on Sunday.
Fifteen clubs would be permanent, rather than have to qualify on merit like for the Champions League.
Widespread condemnation has followed from within the game and beyond, but Guardiola said the lack of information has left him, and other managers of the six clubs, in an uncomfortable situation.
Without criticising his own club, Guardiola made it clear that Europe's biggest football teams should not be protected from failure on the pitch.
"If you ask me about these teams that have been selected I don't know why," the Spaniard told a news conference on Tuesday.
"Sport is not a sport when the relation between the effort and the success, the effort and the reward, doesn't exist. So it's not a sport. It's not sport when the success is already guaranteed. It's not sport when it doesn't matter if you lose."
Asked if it was unfair that he was the first person from within Manchester City to speak about the European Super League in public, Guardiola said he needed more information.
The Spaniard is an admirer of the competitive nature of the Premier League and said it was wrong if clubs such as Leicester City or West Ham United, both challenging for qualification to the Champions League this season, could be denied that dream.
"That's why I said many times I want the best competition as strong as possible, especially the Premier League," he said.
"It's not fair when one team fights and fights and arrives at the top and it cannot be qualified because the success is already guaranteed for a few clubs."
Guardiola said he had only been told of the European Super League a few hours before it was announced.
But since then he, like everyone else, is waiting for the powerbrokers behind the controversial plan to offer more detail.
"Once I have all the information I can give you an opinion. I can give my opinion of what I know today but I don't know more so that's the reality," he said.
"I would love the president of this committee to go out all around the world and say what is the reason why they took that decision. Why some teams will play and the others not. Why Ajax Amsterdam who won four or five Champions Leagues is not there.
"They have the obligation and the duty to clarify as soon as possible, today better than tomorrow."
Guardiola said six clubs should not be demonised, though, adding that all clubs and UEFA have self interest at heart.
(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)