Paris: A report commissioned by UEFA estimates a shortfall of between 2.5 and 3 billion euros ($2.9 to 3.5 billion) over four years for European federations if FIFA adopts its controversial plan to switch to a biennial World Cup, AFP has learned.
European football's governing body presented the findings of the study to the leaders of its 55 member federations on Tuesday.
The report does not take into account the possible additional shortfall for each of the national championships, say French newspapers Le Monde and L'Equipe, who revealed the contents of the document.
UEFA has already opposed FIFA's proposed change to the international calendar which is looking to hold the World Cup every two years from 2028, instead of the usual quadrennial rhythm.
UEFA president Aleksander Ceferin said last month that the change would "lead to more randomisation, less legitimacy, and it will, unfortunately, dilute the World Cup itself".
His sentiments have been echoed by leagues, federations and supporters around the world.
FIFA president Gianni Infantino, however, insists the change would benefit federations and is determined to plough ahead with the idea, saying this week that a final decision will be made "before December."
In addition to the biennial World Cup, the project plans to bring together qualifying matches into a single window in October, or even two in March and October, instead of the current spread of windows throughout the year.
According to Le Monde, the recently-created Nations League, would disappear with the European Championships also moving to a biennial programme.