Prime minister Boris Johnson confirmed the UK Government's backing of football authorities over opposition to proposals for a breakaway European Super League.
In an emphatic response to widespread media reports, UEFA – together with the English Football Association (FA), Premier League, the Royal Spanish Football Federation (RFEF), LaLiga, the Italian Football Federation (FIGC) and Serie A – publicised their collective opposition to the proposals.
One of the sanctions put forward by UEFA was to ban the 12 teams from participating in its club competitions, namely the Champions League and Europa League.
An official statement from the newly formed European Super League followed late on Sunday, European time.
Six Premier League clubs – Manchester United, Manchester City, Arsenal, Liverpool, Chelsea and Tottenham – along with Real Madrid, Barcelona, Atletico Madrid, Inter, Milan and Juventus, are the teams involved.
Bundesliga champions Bayern Munich and Ligue 1 holders Paris Saint-Germain have not been included, with reports suggesting the sides had opted not to join.
The FA warned a European Super League would hurt football "at all levels", stating any closed-shop tournament would go against long-standing principles of the game.
Oliver Dowden, the UK Government's culture secretary, said clubs signing up for any such project would be neglecting their duty to supporters by taking away their say, and Johnson later expanded on his party's stance.
"Plans for a European Super League would be very damaging for football and we support football authorities in taking action," a statement on Johnson's official Twitter account read.
"They would strike at the heart of the domestic game, and will concern fans across the country. The clubs involved must answer to their fans and the wider footballing community before taking any further steps."
UEFA also alluded to FIFA's threat of barring players from the World Cup should they play for teams who choose to participate in a European Super League, and the Professional Footballers' Association (PFA) said it had "substantial concerns regarding the wide-ranging implications of the proposed European Super League concept."
A statement read: "This proposed move would detract from the strength and joy of domestic football and diminish the game for the vast majority of fans across the continent.
"Clubs across all domestic competitions are not equal, each having differing financial starting points. However, success is never guaranteed, often cyclical and always earned.
"We have seen countless examples around Europe of teams outperforming their resources. In recent years, at home in the Premier League, this has resulted in unrivalled global entertainment and sporting drama.
"A system that rewards all clubs for success is paramount. In England, we are privileged to enjoy the most professional teams, the most professional players and in normal times, the highest aggregate attendances across the world. This success is achieved by working together and in solidarity."