Departing Manchester United executive vice-chairman Ed Woodward was involved in plans for the Super League "from day one", says a Premier League club chief executive.
Sky Sports News understands he made the decision because he could not support the owners' plans to join the Super League.
But a Premier League chief executive described that as "laughable", telling Sky Sports News: "He was involved in it from day one."
Joel Glazer was unveiled as a Super League vice-chairman as United were one of the 12 founding clubs that announced they were forming the breakaway league on Sunday night.
- Joel Glazer apologises for Manchester United's ESL involvement
- Ole Gunnar Solskjaer, Michale Carrick address anti-Glazer protesters at Carrington
United went on to quit the European Club Association, while Woodward stood down from his roles with UEFA.
The plans were met with fury by supporters, leagues and governing bodies. UEFA president Aleksander Ceferin said Woodward had backed his Champions League reforms just days before United announced their role in the rival Super League, and branded the executives behind the plans as "snakes" and "liars".
Football's Civil War
Woodward's meeting with PM not about Super League
Woodward did meet Boris Johnson in Downing Street last week but it is understood the Super League was not discussed.
He was introduced to the Prime Minister following a meeting with Number 10 chief of staff Dan Rosenfield on Covid restrictions in football and the forthcoming return of supporters to stadiums.
It is understood the talks took place last Wednesday just days before United were one of six Premier League clubs to announce their intended participation in the breakaway league.
There is a growing feeling among the other 14 Premier League clubs that heads must roll at the six breakaway clubs and apologies will not be enough.
Another chief executive said: "The six of them are scrabbling around spouting all sorts of rubbish to try and defend what they did. They are getting very short shrift."
The 14 are particularly unhappy with the behaviour of executives such as Bruce Buck (Chelsea chairman), Ferran Soriano (Manchester City chief executive), Daniel Levy (Tottenham chairman) and Woodward.
Executives from the six breakaway clubs have spent the past 48 hours trying to say sorry to their own players and managers as well as other clubs.
One executive received a very frosty reception when he arrived at his club's training ground to apologise in person to his first-team squad.
Sky Sports News has been told his players' reaction was a mixture of anger, disbelief and, in some cases, laughter.
Furious Manchester United fans protesting against the Glazer family's ownership blocked both entrances to the club's Carrington training ground on Thursday morning in the wake of the Super League collapse.
"At approximately 9am this morning, a group gained access to the club training ground," read a United statement on Thursday. "The manager and others spoke to them. Buildings were secure and the group has now left the site."
Around 20 protestors accessed Carrington, carrying banners, and made their way to reception and to the first-team training area. Police were called to the training ground.
Ole Gunnar Solskjaer was joined by Michael Carrick, Darren Fletcher and Nemanja Matic in addressing the fans, who then dispersed.
Neville: Woodward knew his time in football was finished
Club legend Gary Neville appeared to welcome Woodward's departure from United, tweeting a waving emoji as the news broke on Tuesday.
Speaking on Sky Sports, Neville went on to say Woodward resigned as he 'knew his time in football was finished', adding: "We obviously don't know why the timing is now.
"The leeches could have thrown him under a bus, there's no doubt about that. Or it could have been that the sensible thing has happened that Ed Woodward knew it was going to get pretty hot in the kitchen for him in the next few months and he needed to get out of there.
"The fact of the matter is, not just Ed Woodward, every single executive who goes and sits at the Premier League table, every single executive who is on these UEFA or FIFA committees, they need throwing out of that club because there is no way they can turn up again and be trusted."
Football's Civil War - Sky Sports News special
Join us at 5pm this evening for a two-and-half-hour Sky Sports News special show looking into how the breakaway Super League rocked football to its very core and asks what now for Britain's national game.
The show will include new interviews with Pep Guardiola, Gary Neville and Nemanja Matic and we will be joined by John Barnes, Alan Smith, Raphael Hongistein and others to cover one of the biggest stories in British Sport for decades.
Watch live on the Sky Sports News YouTube channel as well as Sky Sports News, Sky Sports Football and Sky Sports Premier League.