The three continental associations each signed a new open letter to the "football family" on Monday, without naming Infantino specifically but referring to a leader who "abandoned their duty" by breaking trust "through deception".
In the three-page document they again criticised the president's World Cup sale plans and rejected FIFA's claim that they had been a "mistake", adding: "There remains no recognition that attempting to sell an interest in the FIFA World Cup was a profound failure of judgment - not just a procedural misstep, but a fundamental breach of trust with the very institutions FIFA exists to serve."
UEFA, CONMEBOL and AFC had been the three confederations to reject Infantino's plan before its scrapping, while UEFA went further and announced a boycott of FIFA competitions - and last week confirmed the threat remained while Infantino is still in post.
The associations also hit out at the manner of a FIFA management committee meeting held in Morocco last Wednesday - a meeting which which ended with a statement publicly backing Infantino - for not instead addressing FIFA's wider senior leadership at its base in Switzerland.
"It is not the conduct of a custodian of the game, but of one who believes the game is answerable to him," the letter read. "There is silence where there should be accountability, distance where there should be openness."
The letter came around 24 hours after FIFA itself had hit out at "a concerted and ongoing effort by some to undermine" the governing body and president Infantino over claims surrounding his conduct at UEFA.
UEFA confirmed on Saturday a "departure payment" was made to a female employee alleged to have been in a relationship with Infantino when he was the European organisation's general secretary.
The Daily Telegraph reported the woman received a six-figure sum and UEFA confirmed a payment was made along with covering the fees for an MBA course, adding it was "in line" with regulations at the time.
The allegations intensified the position of Infantino, who worked at UEFA for 16 years and was its general secretary between 2009 and 2016 before being elected FIFA president, following his aborted plan to sell off stakes in the World Cup to private investors.
While not directly referencing UEFA's statement, FIFA accused Infantino's critics of trying to weaken his authority and have him removed from his role without a due re-election process.
A statement said: "It is increasingly evident that there is a concerted and ongoing effort by some to undermine FIFA and its president.
"Those who do not have the support of FIFA's member associations should not seek to achieve through allegation, insinuation or misinformation what they cannot achieve through FIFA's established democratic processes.
"Recent reporting has included unsubstantiated assertions and demonstrably false claims concerning FIFA and its president. Speculation and insinuation should not be presented as fact, and repetition does not make an allegation true.
"The FIFA president has dedicated more than 30 years of his professional life to European and world football, contributing to significant change in the game and, in particular, to broadening access, resources and opportunity across world football
"Change inevitably challenges established interests, but disagreement with that change cannot justify efforts to undermine the democratic mandate of FIFA's president or the institution he was elected to lead.
"FIFA welcomes legitimate scrutiny. But scrutiny is not a licence to distort facts, amplify unsubstantiated allegations or manufacture distractions designed to undermine progress. Where reporting is inaccurate or misleading, FIFA will challenge it directly and vigorously.
"FIFA's responsibility is to its 211 member associations and to football around the world. We will not be distracted or diverted from strengthening the organisation, delivering for our member associations and continuing the work of making football truly global. Through the FIFA president and the FIFA administration, our focus remains firmly on that mission, and we are more determined than ever to fulfil it."
Following the Daily Telegraph claims on Friday, a FIFA spokesperson was reported to have told the newspaper Infantino "strongly denies these categorically untrue allegations".
A UEFA spokesperson said: "We are aware of the allegations and can confirm a departure payment was made to the individual in question, coupled with the payment of fees for a MBA course at a local business school.
"The payment was in line with the regulations that existed for departing staff at the time.
"Such regulations have been tightened since 2016 and the current staff regulations - which apply to all UEFA employees at whatever level - reflect those found in a modern, high-profile organisation."
