Australia's professional footballers' union has sharply criticised Fifa's contentious plan to introduce private investors into the World Cup and other major tournaments, accusing the governing body of sidelining players and fans while pressuring member associations to approve the proposal.

Professional Footballers Australia (PFA) declared that the sport is facing "a battle for its soul" as commercial interests increasingly seek to influence its most prestigious competitions.

"The PFA is disturbed by the lack of transparency surrounding the proposal and the absence of meaningful consultation with those that generate the value that Fifa is seeking to exploit - the players and the fans," the union stated in a scathing release.

"At a time when football desperately requires greater transparency, accountability and good governance, proposals of this significance raise questions about who the game is run by and in whose interests. These tournaments should not be for sale."

The PFA's concerns echo those of Fifpro, the global players' union, which warned earlier this week that the plan could irrevocably alter the incentives underpinning the competitions where players forge their careers.

Fifa's plan to create a $20 billion subsidiary to run the World Cup and its other events includes offering minority stakes to private investors to raise up to $4.2 billion and the promise of a significant funding boost for member associations.

Many of the sport's regional confederations and national associations have claimed they were blindsided by the plan, though only Europe's governing body, Uefa, has outright rejected it.

Fifa president Gianni Infantino, in a video statement on Wednesday, insisted the proposal was not mandatory and merely initiated a consultation process. He offered member associations $40 million each if they agreed to the proposal by September 19 as part of a $10 billion package to become available from January 1, 2027.

If rejected, the package would revert to $2.7 billion previously offered - around $10 million per member association.

The PFA expressed strong reservations about this timeline.

"We are equally concerned about the pressure being placed on Member Associations, including Football Australia, to expeditiously consider this proposal when it will have profound and irreversible consequences for the ownership and governance of football's premier competitions," it added.

Football Australia has declined to state a position, indicating it has requested further details from Fifa to properly assess the strategic, commercial, and governance implications.

Fifa intends to put the decision to a vote among its 211 consultation members, followed by its executive Council. Despite Uefa's firm stance, the powerful European bloc of 55 member associations is not entirely united in opposition, with the Czech FA's president suggesting he could foresee a "positive impact" from Fifa's intentions.

The African confederation's executive committee is scheduled to meet next week to evaluate the proposal, while South American governing body Conmebol and the Oceania confederation have yet to comment publicly.