Aleksander Ceferin has said that clubs are free to enter into a breakaway competition but should they do so they will not be able to take part in UEFA competitions.
The UEFA president, speaking at the Financial Times' Business of Football Summit, addressed the remaining agitators for a breakaway European Super League; Juventus, Real Madrid and Barcelona, three clubs who have been pursuing legal action against European football's governing body ever since the initial project imploded back in April last year.
Liverpool were among the 12 clubs to try and launch a breakaway ESL competition last year, a plot that crashed and burned just 48 hours from its launch following a fierce backlash from fans.
The Reds, Manchester United, Arsenal, Chelsea, Manchester City, Tottenham Hotspur, Inter Milan, AC Milan and Atletico Madrid all renounced their involvement in the competition in the days following its failed launch, with only Barcelona, Real Madrid and Juventus remaining wedded to the project.
READ MORE: Liverpool's clash with Man United postponed ahead of potential fixture pile-up
READ MORE: Liverpool player ratings as Takumi Minamino and James Milner impress vs Norwich
Liverpool's principal owner, John Henry, had filmed a video apology to fans in the wake of the ESL's collapse and pledged to fund the costs that were associated with it.
Since then the Reds have launched a Supporters Board after working with the Spirit of Shankly supporters group and other Reds fan groups, where any future decision over joining a breakaway league would have to receive consent from the newly formed Board.
And with the three rebel clubs continuing to agitate for an ESL as they seek to try and find new ways to bring in revenue after their finances were exposed due to the pandemic, Ceferin has made his stance clear.
"I am tired of talking about this nonsense," Ceferin said today.
"First they try to launch during a pandemic, now we hear that they are trying to launch in the middle of a war. Do I have to speak more about these people? They obviously live in a parallel world.
"While we are saving players together with other stakeholders, while we are working to help in a terrible situation they work on a project like that.
"Honestly speaking, they can pay whoever they want to write that this is a nice project, that they are full of solidarity and give some charity to small clubs. This is a complete nonsense and everybody except them knows it.
"One of them even called me after and apologised. Now they go again.
"To them fans are customers, for us fans are fans. It is interesting that they are criticising UEFA and ECA, one of them (Agnelli) was chairman of the ECA. Fans aren't important to them as fans launched a petition, they don't care about that.
"Let me just say that they can play their own competition, nobody forbids them that.
"But if they play their own competition they cannot play our competition."
The Champions League, the most lucrative competition for Europe's major teams, is set to undergo reform from 2024 via a 'Swiss Model', where the number of teams will increase, meaning more games for teams and more media revenue to be delivered, with the next cycle of media rights for UEFA's Champions League, Europa League and Europa Conference League set to be worth in excess of £12bn.
Some have argued that the reform leans heavily in favour of the bigger clubs, with the mooted prospect of places for clubs based upon historical performance in Europe a bone of contention.
But Ceferin argued otherwise.
"It is completely different thing," he said.
"We are discussing with all our stakeholders, we are discussing with the leagues, we are discussing with the clubs, the ECA. It is not 'Super League-ish', it is everything but the Super League.
"We have not clarified the final decision, but for anyone to compare the reform of the Champions League to the Super League is not serious.
"We have 32 teams in the Champions League now and the plan is to have 36. It will be more places for smaller and mid-sized teams."
In their latest set of accounts for 2020/21, published on Friday, Liverpool confirmed that the ESL costs would be met personally by Henry.
The financial report read: "The Directors have considered and accounted for all costs attributable with its intended participation and subsequent withdrawal from the European Super League, this also includes the owner's commitment as at year end to fund all current and any future costs attributable to the club's involvement."
Back in September, Liverpool reaffirmed their ESL stance in a statement which said: "Our involvement in the proposed ESL plans has been discontinued.
"We are absolutely committed to following that through and there should be no ambiguity to suggest otherwise."
