The battle over the future of the Champions League will resume on Monday and Tuesday when the European Club Association (ECA) meets in Geneva and the leadership faces rebellion from members.
ECA, led by Juventus chairman Andrea Agnelli, is closely involved in proposals to reshape Europe's main club competition from 2024.
The proposals were presented by European football's governing body Uefa in May although details had leaked earlier.
The reforms include the introduction of weekend fixtures, four groups of eight, and a tiered system with relegation and promotion that would see the top six teams in each group automatically qualify for the following year's competition.
ECA, which boasts of "more than 230 members", faced an outcry from many of those clubs and from national leagues which would be hit hard by the scheme.
"A semi-closed league with more matches... threatens to enormously impoverish the Spanish league," said Javier Tebas of La Liga.
England's Premier League issued a statement saying: "The domestic game should continue to be the priority for professional clubs."
Opponents say the plan is designed to guarantee the income of a handful of big clubs.
"This reform would especially harm medium and small clubs," said Wanja Greuel, the president of Young Boys of Berne, the reigning Swiss champions.
"It eliminates the access to the top flight of European competitions through domestic leagues. Fans will gradually lose interest in domestic leagues and those leagues would be further economically damaged."
Last month Uefa announced it was cancelling a meeting with the ECA and the European Leagues, a wider body representing more than 900 European clubs, scheduled for September 11.
Uefa President Aleksander Ceferin said he wanted to "collect feedback" from member federations.
The cancellation of the meeting "reveals strong opposition," said Bernard Caiazzo, president of French Ligue 1 club Saint Etienne, who are outspoken opponents of the plan.
"When you close the supreme competition to 90 percent of clubs, you kill the dream for a middle-sized club reaching it," said Caiazzo.
He gives the example of Lille, who dramatically improved last season, finished as French league runners up, but who from 2024 "could no longer experience this fairytale of moving from 17th place in Ligue 1 to the Champions League in the space of 14 months".
On Friday, both Uefa and the ECA struck a cautious note.
"We need to take into consideration the clubs' feedback," ECA secretary general Michele Centenaro said. "Domestic football (leagues) must be protected and, at the same time, we must try to better reward European cup performances."
Uefa's Director of Competitions Giorgio Marchetti said there was "no pressure to make a decision" and discussions would continue into 2020.
Both Uefa and ECA both regularly deny paternity of the project.
According to a source close to the talks, however, the reform is the responsibility of Marchetti, who was general secretary of the Italian league before joining Uefa, in collaboration with his ECA counterpart, Belgium's Diederik Dewaele, who was previously with Uefa.
The clubs are playing the same ambiguous game, a source said.
"Five or six large influential European clubs within the ECA have a large part in the reform proposal but each tries to get it endorsed by the other so as not to lose credibility."
Among these are Agnelli's Juventus and other big clubs worried that income from the domestic leagues they dominate will stagnate.
"It's interesting to PSG because it creates wealth for all of football," said Victoriano Melero of Paris Saint-Germain.
Barcelona and Ajax are in favour. Real Madrid are reportedly backers as well.
Smaller clubs on the ECA executive -- Lyon, HJK Helsinki and Legia Warsaw -- are also in favour. Marseille are also supporters.
Other big clubs have been cagey.
In Italy, Roma and the two Milan clubs abstained in an Italian league vote on the plan.
In Germany, Bayern Munich, one of the presumed authors of the scheme, and Borussia Dortmund have spoken against it.
This summer, ECA held "club forums" at which it continued to present an unchanged scheme despite repeated hostile reactions.
After a meeting of its executive board on August 16, ECA said in a statement: "Our members have made clear that the current structure of Uefa Club Competitions is not serving the interests of the majority of clubs, particularly those outside of the largest domestic competitions."
Even if it will take longer than expected, the key elements of the plan seem to be on track, Raffaele Poli, a researcher at the International Centre for the Study of Sport in Neuchatel.
"The proposal set the cat among the pigeons," said Poli.
He said that "nothing is decided" but, he predicted, "there will still be more European matches, groups with 16 matches and a strengthening of the elite."
"The percentage of clubs that are against the project or undecided is higher than the percentage of clubs that are in favour," said Saint Etienne's Caiazzo.