The European Super League can no longer proceed, Juventus boss Andrea Agnelli confirmed on Wednesday, as Spain’s Atletico Madrid, Italy’s Inter Milan, and six English teams abandoned the breakaway competition after intense criticism.

Twelve of Europe's leading football clubs from England, Italy and Spain announced a breakaway league on Sunday but after 48 hours of massive pressure from fans, politicians and even British royals, the six English clubs backed out on Tuesday.

Agnelli said he still believed in the merits of the Super League despite the overwhelming criticism and had no regrets about how the breakaway had been conducted.

"I remain convinced of the beauty of that project," Agnelli told Reuters, saying it would have been the best competition in the world. "But admittedly [...] I mean, I don't think that that project is now still up and running."

Atletico Madrid joined Inter Milan on Wednesday in pulling out of the project.

A source close to Inter Milan had earlier confirmed to Reuters they were no longer interested in the project “in light of the latest developments”.

The founding members of the league were English clubs Arsenal, Chelsea, Liverpool, Manchester City, Manchester United and Tottenham Hotspur, Italy's Juventus, Inter and AC Milan, and Spain's Real Madrid, Barcelona and Atletico.

Agnelli's Juventus, AC Milan, Barcelona and Real Madrid are the four clubs yet to announce their withdrawal but that position is expected to change within hours.

Liverpool's principal owner John Henry apologised in a video on the club's website and social media on Wednesday.

"It goes without saying but should be said that the project put forward was never going to stand without the support of the fans," he said.

"I alone am responsible for the unnecessary negativity brought forward over the past couple of days. It's something I won't forget. And shows the power the fans have today and will rightly continue to have."

Having triggered an enormous backlash from players, fans and football authorities, the Super League had said late on Tuesday it would reconsider and look to “reshape” the project, while stopping short of throwing in the towel.

'Beautiful day'

The Super League had argued that it would increase revenue for the top clubs and allow them to distribute more money to the rest of the game.

However, the sport's governing bodies, other teams and fan organisations said the breakaway would only boost the power and wealth of the elite clubs, and that the partially closed structure went against European football's long-standing model.

Players, fans and pundits celebrated the U-turns of the English teams.

"This is the right result for football fans, clubs, and communities across the country. We must continue to protect our cherished national game," British Prime Minister Boris Johnson said. "I welcome last night’s announcement."

"What a beautiful day for football. Let's keep playing, let's keep fighting, let's keep dreaming," said Manchester City defender Benjamin Mendy.

The news dominated the front page of Wednesday's newspapers in Britain.

"Defeat of Greed", declared the Daily Mail's front page headline while the i paper summed up the withdrawal as "Own Goal".

The Daily Telegraph proclaimed a "victory for fans" while the Times said the clubs involved had bowed to "fan fury".

A top official from the Council of Europe termed the project an unfortunate initiative and called on an inter-governmental sports coordination body to urgently discuss the ramifications of the proposed breakaway.

Amid celebrations over the collapse of the project, anger remained. Some pundits said the owners of the English teams would never be forgiven.

"They were going to sell the souls of our major football institutions," said Liverpool great Graeme Souness.

“I don’t know how these clubs will manage to get back on-side.”