A breakaway European Premier League tournament, which would effectively replace the Champions League, could be doomed to failure as it would struggle to get crucial approval from governing bodies, sources have told ESPN.

Sky News reported on Tuesday that a $6 billion (£4.6 billion) funding package had been put in place for the competition, which would feature 16 or 18 of the biggest clubs, in league format, and is supported by Liverpool and Manchester United. The two Premier League clubs were behind a failed attempt to reshape English football last week, when Project Big Picture was rejected outright.

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FIFA, which has already set up an expanded summer Club World Cup and was due to begin in China in 2021 until the coronavirus crisis reshaped the football calendar, is reportedly a driving force behind the European Premier League.

The competition would need approval from UEFA, and sources told ESPN that European football's governing body had received no information on any European Premier League idea as of Tuesday. La Liga giants Barcelona, who would be expected to be approached, told ESPN that they were "not aware of these talks."

Sources said that national associations would also need to grant European licences, and the impact upon domestic leagues would be a considerable barrier to overcome.

La Liga president Javier Tebas told ESPN: "The authors of this idea, if they really exist because there is nobody actually defending it, not only show total ignorance of the organisation and customs of European and world football, but also a serious ignorance of the audiovisual rights markets.

"A project of this type will mean serious economic damage to the organisers themselves and to those entities that finance it, if they exist, because they're never official. These 'underground' projects only look good when drafted at a bar at 5 in the morning."

The latest reports of a breakaway competition, of which there have been several iterations in recent years, come at a crucial time for UEFA with the format for the 2024-27 Champions League cycle due to be agreed next year. The biggest clubs are eager to play more high-profile fixtures against their peers, and also receive a more lucrative financial package. Plans to expand the competition from 32 to 36 clubs, adding four group-stage fixtures for each club, are expected to be agreed.

A European Premier League would decimate the Champions League, UEFA's flagship and most lucrative tournament, of its marquee clubs. Twelve months ago, the Financial Times and New York Times reported Real Madrid president Florentino Perez had proposed a two-division world soccer league which UEFA president Aleksander Ceferin described as "an insane plan." UEFA has not issued any statement on the latest reports.

Clubs would continue to play in their domestic league, with European Premier League fixtures effectively replacing Champions League match dates. However, it is reported that financiers may want to play games during the day on weekends to maximise TV audiences in Asia, which would put it in conflict with the national associations.

ESPN has been told that national associations will almost certainly be opposed to any change that may affect the competitive balance of their leagues, including offering guaranteed places in European competitions which would devalue their own leagues and strengthen the position of a handful of clubs.

It may be particularly troublesome for the Premier League. While Liverpool and Manchester United are reported to be at the forefront of discussions, there would not be a place for all of the "Big Six." If locked out of the European Premier League, then whoever is left out from Arsenal, Chelsea, Manchester City and Tottenham Hotspur would be likely to join those in opposition.