The UK government said it will do “whatever it takes” to prevent a breakaway European Super League involving six leading English clubs.
Boris Johnson said ministers would be working to make sure the league did not go ahead in the way being proposed.
The Duke of Cambridge also said he shared fans’ concerns about “the damage it risks causing to the game we love”.
But the president of Real Madrid told a Spanish TV show: “We are doing this to save football at this critical moment.”
Florentino Perez, president of Real Madrid, said the decision to create the new league was in part taken because “young people are no longer interested” in the game.
Speaking for the first time since the league was announced, Mr Perez said: “Audiences are decreasing and rights are decreasing and something has to be done. We are all ruined. Television has to change so we can adapt.”
The 12 founding members of the league, which includes Real Madrid plus three yet to join – would be permanent and never face relegation.
In a joint announcement six English clubs — Arsenal, Chelsea, Liverpool, Manchester City, Manchester United, and Tottenham Hotspur three teams from Italy — AC Milan, Inter Milan and Juventus — and three from Spain — Atlético Madrid, Barcelona and Real Madrid — laid out plans to form a breakaway competition.
The competition would have 20 teams and another five sides would have to qualify each year for the competition.
Matches would take place midweek and rival the existing Champions League.
But the president of European football’s governing body Uefa, Aleksander Ceferin, warned players who play for teams in the ESL would be “banned from the World Cup and the Euros”.
As opposition to the plans gathered momentum, Prince William, President of the Football Association, said in a tweet: “Now, more than ever, we must protect the entire football community – from the top level to the grassroots – and the values of competition and fairness at its core.”
And broadcaster Sky Sports said: “We have not been involved in any discussions with the proposed breakaway European Super League.”
“We are completely focused on supporting our long term football partners in the UK and in Europe, already providing fans with the best live action from the best football competitions in the world,” the company added.
In a statement to MPs in the House of Commons, Culture Secretary Oliver Dowden criticised the so-called “big six” English clubs for going “against the very spirit of the game”.
He added club owners “should remember that they are only temporary custodians of these clubs and that they forget fans at their peril”.
Mr Dowden said he had spoken to Uefa and the Football Association, who both opposed the move by the 12 clubs, adding that, “if they can’t act, we will”.
“We will put everything on the table to prevent this from happening,” he told MPs.
“We are examining every option from governance reform to competition law and mechanisms that allow football to take place.
“We will be reviewing everything the Government does to support these clubs to play. We will do whatever it takes to protect our national game.”
Earlier, Prime Minister Boris Johnson said the government was “going to look at everything that we can do with the football authorities to make sure that this (plan) doesn’t go ahead in the way that it’s currently being proposed”.
Downing Street said ministers were looking at a “range of options”, including a German-style system of fan ownership of clubs and clawing back coronavirus support loans.
But Labour urged ministers to do more, with shadow culture secretary Jo Stevens saying it was “time for the government to get off the subs bench and show some leadership on the pitch because we need reform of football”.
She added: “It’s not as if there’s been a blockage here in Parliament preventing the government from taking action to sort the problems out.”
Fans and pundits have expressed revulsion at what they claim would be an unfair competition that would lock many teams out of top European football.
Match of the Day host and former England footballer Gary Lineker said it was “a time of great concern”, adding that if the ESL went ahead as planned, it would have “massive ramifications” on the domestic game.
“It will wreck the pyramid system (of leagues, promotion and relegation) that has been so important to local football clubs, communities and teams, and it takes out the competition.”
Around 68% of football fans strongly oppose the creation of the ESL, while only 14% support it, according to a YouGov survey of 1,730 fans.