Uefa president Aleksander Ceferin will lead an emergency meeting of all 55 member associations on Thursday.

Uefa will hold an emergency meeting on Thursday afternoon to discuss its response to the controversial World Cup stakeholder plans proposed by Fifa and its president Gianni Infantino.

European football's governing body kept up its offensive over the plans after it was discovered Fifa had sent a letter, seen by the BBC, to all 211 member associations giving them until 19 September to decide if they want to accept the deal, and with it the first $20m (£15.05m) of an initial $40m (£30m).

"We have learned of Fifa's deadline to associations to support their proposals or have the one-off payout offer withdrawn," said Uefa. "This says everything you need to know about this plan." It was Uefa's second statement on the issue. The first claimed Fifa had "crossed a line".

It is not known precisely what will be discussed at the meeting, which will be held virtually. Many associations, including the Football Association, are furious at only learning through the media of the proposal to sell a 20% stake in Fifa competitions to private finance - led by the Thrive Eternal investment vehicle owned by Joshua Kushner, the brother-in-law of Donald Trump's daughter Ivanka.

FA chairwoman Debbie Hewitt was among the Fifa vice-presidents not given advance warning. Uefa's unease has been echoed by the Asian, South American and North and Central American Confederations. Three of the 2026 World Cup semi-finalists are among Uefa's 55 members. It knows the nuclear option of its members pulling out of the tournament would severely damage the financial viability of the concept.

That is very much viewed as the outer edge of what is possible, particularly as one Uefa member has said it is broadly in agreement with Infantino's proposals. "We can see the pragmatic benefits for Czech football," said Czech Republic FA president David Trunda.

Is World Cup sell-off plan a step too far by Infantino? Fifa offers $40m if nations back controversial plan.

After widespread condemnation of both the proposals and the manner in which they have been created, Fifa released an eight-page document highlighting the reasons behind them on Wednesday evening. Fifa said its view was that "too little of football's growing commercial value has reached the parts of the game that need it most".

It has been pointed out the sums being spoken about are more than some member associations spend annually and questions have been raised about the auditing of money Fifa already hands over in some parts of the world. Despite this, Infantino feels the proposals would help provide funding for "better pitches, stronger national teams, more pathways for young players, and greater support for women's football".

In a video released by Fifa on Wednesday, Infantino defended the plans, calling them "an offer, not an obligation". "It's part of a democratic process - a consultation process - and, above all, it is an opportunity but not an obligation," he added. "It is a golden opportunity to turbocharge the development of the game globally."

Fifa points to the qualification of Cape Verde, Curacao, Jordan and Uzbekistan for the World Cup for the first time as an example of the positive benefits of its work, although that was, in part, due to the expansion of the competition to 48 teams.

Fifa also cites Formula 1, La Liga, Ligue 1 and the Bundesliga as examples of other sporting organisations that use "dedicated commercial operations". It says private investors would "absolutely not" have any influence over the World Cup.

Wednesday saw a stream of comment on the issue, most of it negative. The European Leagues organisation said Fifa's proposals represented "a reckless and divisive development for world football". "The World Cup should not be for sale. It is not the Fifa president's private equity asset," a statement read.

Global players' union Fifpro called on Fifa to "reconsider its proposal without further delay". It said it had "noted with deep concern the proposal to transform the World Cup and other Fifa competitions into investable assets for private capital". Fifpro added that such a move "would fundamentally and irreversibly reshape the incentives underpinning the competitions" and it was "particularly troubling that a project of this magnitude has been developed largely behind closed doors".

La Liga president Javier Tebas accused Infantino of trying to buy votes before the next Fifa congress in March. "It doesn't seem like a reform. It seems like an electoral campaign financed with the future of football," Tebas said. "Development cannot be used to buy votes or silences. The competitions and commercial rights of Fifa are not the personal patrimony of Infantino."

"Whoever mixes politics, discipline, money and power without transparency cannot lead anything. Infantino is not the solution to Fifa's governance. He is the problem."

Hans-Joachim Watzke, current vice-president of the German Football Association (DFB) and president of Borussia Dortmund, told Kicker magazine that Fifa's plans are an "absolute attack on football". He said: "A line has been crossed here. If European football stands united against these plans, that carries a great deal of weight."

Fifa opens disciplinary proceedings against Argentina.

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