UEFA president Aleksander Ceferin has branded the planned European Super League as a "disgraceful, self-serving proposal" fuelled by greed, as well as confirming players from the 12 breakaway clubs involved will be banned from international football.
The 'big six' from the Premier League have collaborated with Atletico Madrid, Barcelona, Inter, Juventus, Milan and Real Madrid to reveal plans for a new midweek club competition.
Those founder members would automatically qualify each season no matter where they finished in their respective domestic leagues.
Speaking during a conference call to reveal "dynamic" changes to UEFA's current European club tournaments, Ceferin made clear how results on the pitch should always decide who participates, rather than a "closed shop run by a greedy few".
"We began this project to modernise the competitions in 2019 judged by the principle it should be: an exercise in inclusive leadership," Ceferin told the media.
"At the start of the process, we were driven by a desire to help all UEFA club competitions into something even better than the spectacles we know today. With the unanimous support of the European Club Association (ECA), we consulted widely across the game.
"Teams will always qualify and compete in our competitions on merit, not a closed shop run by a greedy, select few. That was our decision from the beginning.
"Any club, any fans should still have the dream of participating in the Champions League based on their results on the pitch."
The European Super League plan has come in for widespread criticism and Ceferin did not hold back in his own assessment, as well making clear the ramifications it will have for players outside of club football.
"I must address the extraordinary situation that has developed on the eve of this announcement," he continued.
"I cannot stress more strongly at this moment that UEFA and the footballing world stand united against the disgraceful, self-serving proposal in the past 24 hours from a select few clubs in Europe that are fuelled purely by greed above all else.
"Not only is the football world united, but society is also united, governments are united. It's part of our culture – we are all united against this nonsense of a project.
"We have the English FA, Spanish Federation, Italian Federation, Premier League, LaLiga, Serie A, and also FIFA and all our 55 member associations unanimous in opposition to this cynical plan that are completely against what football should be.
"Our game has become the greatest sport in the world based on open competition, integrity and sporting merit. We cannot allow, and we will not allow that to change, ever. Never.
"As previously announced by FIFA and the six confederations, the players that play in the teams that might play in the closed league, will be banned from playing in the World Cup and the Euros. They will not be able to represent their national teams in any matches."
UEFA announced plans for Champions League expansion that will see an increase to 36 teams as the present format - whereby there are eight pools of four – will be scrapped.
Instead, each team will play 10 group games before advancing to a last-16 knockout format. The changes are due to be introduced for the 2024-25 season.
"Whoever thinks the Super League and UEFA are all about money is not right. Super League is only about money, money of the dozen – I don't want to call them the dirty dozen," Ceferin said.
"UEFA is about developing football, about financing what should be financed, that our football and our culture survives. Some people do not understand it.
"The reforms preserve the value of the domestic game by retaining the principle that domestic performance should be the key to qualification – this should, and will not, ever change.
"The European game is the greatest success story of the modern sport, and there's a reason why – because of its pyramid, it's long history. We are constantly adapting the European competition to ensure it is more and more interesting, more and more modern, but the principles cannot change.
"Solidarity is something that cannot change, but for some people solidarity doesn't exist, unity doesn't exist. The only thing that exists is their pockets."