Atletico Madrid and Inter became the lastest clubs to pull out of the European Super League on Wednesday, with the project on the brink of collapse. 

Only Real Madrid, Barcelona, AC Milan and Juventus officially remain, after England's 'Big Six' teams as well as Inter Milan were the first to withdraw from the hugely controversial competition.

"The Atletico Madrid Board of Directors, meeting this Wednesday morning, has decided to formally communicate to the Super League and the rest of the founding clubs its decision not to finally formalize its adherence to the project," the Spanish side said in a statement.

"Atletico Madrid made the decision last Monday to join this project in response to circumstances that no longer exist today. 

"For the club, harmony is essential between all the groups that make up the rojiblanco family, especially our fans. 

"The first team squad and their coach have shown their satisfaction with the club's decision, understanding that sporting merits must prevail over any other criteria."

Atletico are one of three La Liga outfits involved in the breakaway tournament, with Real Madrid and their president Florentino Perez at the heart of the project. 

But the new league looks dead in the water after Manchester City, Chelsea, Manchester United, Liverpool, Arsenal, Tottenham as well as Inter all pulled out.

Inter Milan have also withdrawn from the European Super League project after the departure of all six English clubs, the Italian club announced on Wednesday.

"FC Internazionale Milano confirm that the club is no longer part of the Super League project," the team said in a statement.

The Chinese-owned club are the first Italian side to withdraw from the 12-team project which also includes Juventus and AC Milan.

The two teams now the likes of the Premier League big six in officially withdrawing from the Super League.