Negative reaction to the proposed Super League in Europe continued to mount Tuesday, with FIFA President Gianni Infantino warning the 12 breakaway clubs they “cannot be half in and half out” of the continent’s established soccer structure.

“If some elect to go their own way then they must live with the consequences of their choice, they are responsible for their choice — concretely this means, either you are in, or you are out. You cannot be half in and half out. This has to be absolutely clear,” Infantino told the UEFA congress in Montreux, Switzerland.

In England, Premier League representatives said they “unanimously and vigorously rejected the plans for the competition” after meeting to discuss potential actions against the six prospective English members of the Super League.

On Sunday, 12 powerhouse clubs from England, Spain and Italy announced they would break away from the UEFA Champions League to form the permanent backbone of a new Super League, an annual 20-team competition that would in essence decide the club champion of Europe. Since 1955, that title has been decided by the Champions League, which would lose much of its luster without the breakaway teams, who would still compete in their domestic leagues along with the new competition.

The move — a potential cash cow for the teams involved but also one that would shut out nearly all of Europe — has been met with condemnation from many European soccer fans as well as from the continent’s power structure. On Monday, UEFA President Aleksander Ceferin called the 12 breakaway teams “snakes” and said they were spitting “in the face of football lovers.”

Premier League chief executive Richard Masters on Tuesday led a meeting of the 14 top-tier English clubs who were not involved with the proposal. Afterward, the Premier League issued a statement calling on the six English breakaway clubs — Arsenal, Chelsea, Liverpool, Manchester City, Manchester United and Tottenham Hotspur — to cease their involvement with the Super League and saying the Premier League “is considering all actions available” to stop the new venture.

English players and managers also got involved Tuesday, including those with the breakaway clubs. Manchester City’s Pep Guardiola, one of the most prominent managers in world soccer, was bluntly critical of the proposed closed league, telling reporters, “It is not a sport where success is already guaranteed, or it is not a sport when it doesn’t matter where you lose.” Liverpool captain Jordan Henderson called for an emergency meeting Wednesday between the captains of all 20 Premier League clubs.

Infantino, meanwhile, expressed hope that the Super League idea simply would go away.

“We can only and strongly disapprove of a Super League which is a closed shop, breakaway from current institutions,” he said. “No doubt whatsoever of FIFA’s disapproval. Full support to UEFA.

“We hope that everything will go back to normal, that everything will be settled, but always with respect, always with solidarity and with the interests of national, European and global football.”

UEFA has threatened to block the 12 breakaway teams from next season’s Champions League and the second-tier Europa League, even if the Super League is not yet operational (it hopes to be up and running in August). On Tuesday, meanwhile, British Prime Minister Boris Johnson told leaders of the Premier League, the Football Association and English fan groups that he was considering legislative options to stop the six Premier League teams from joining the breakaway competition.

“He reiterated his unwavering support for the football authorities and confirmed they have the Government’s full backing to take whatever action necessary to put a stop to these plans,” Johnson’s office said in a statement.

“The Prime Minister confirmed the Government will not stand by while a small handful of owners create a closed shop.

“He was clear that no action is off the table and the Government is exploring every possibility, including legislative options, to ensure these proposals are stopped.”

A Johnson spokesman told reporters the prime minister could consider preventing players of the clubs involved from getting work visas and withdrawing police funding on match days for the breakaway teams.

But Florentino Pérez, president of breakaway club Real Madrid who has been named Super League chairman, said he’s “completely sure” the participants of the new competition won’t be thrown out of this season’s Champions League, and he criticized that competition’s format, saying it’s only “attractive from the quarterfinals” onward (the tournament in essence starts with a group stage in which teams play six games against three other clubs before moving on to a knockout round).

“We play against small teams that aren’t attractive. Young people prefer to entertain themselves with other things. But if we do it all season, five games on Tuesday, five on Wednesday, that would be unstoppable,” Pérez said during an appearance on the late-night Spanish talk show “El Chiringuito.”

“What would bring in money is the 15 clubs playing each other every week. That’s the greatest show in the world, there’s nothing like it,” he added. “A Real Madrid-Manchester [United] or a Barcelona-Milan is more attractive than Manchester [United] against a small club.”

This year’s Champions League is down to the semifinals, with three of the four remaining teams — Real Madrid, Chelsea and Manchester City — planning to play in the Super League.

Soccer legend David Beckham, who played for three of the Super League clubs during his career, expressed his dismay for the idea in an Instagram post.

“As a player and now as an owner I know that our sport is nothing without the fans,” he wrote. “We need football to be for everyone. We need football to be fair and we need competitions based on merit. Unless we protect these values the game we love is in danger.”

Beckham is president and co-owner of Inter Miami CF, a team that plays in the closed system of Major League Soccer in the United States.

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