UEFA president Aleksander Ceferin has reiterated his opposition to FIFA's plans to stage a biennial World Cup, saying the women's tournament or the Olympics would be affected if they were held in the same year as the finals.
The European soccer governing body and its South American counterpart CONMEBOL have strongly opposed the idea which FIFA president Gianni Infantino has said would create an extra £3.3bn in revenues for the world soccer organisation.
"Europe and South America are against (the plan) and those are the only (continents with) World Cup winners in history. The problem is that the World Cup has to be every four years to be interesting," Ceferin said at the Expo 2020 Dubai fair.
"Second, if it would be every two years, it would cannibalise women's football because it would be at the same year as the women's football (World Cup), other sports, the Olympic Games - many mistakes.
"It's simply a bad idea and it will not happen because it is a bad idea, not because we are opposing it."
FIFA's plans had the International Olympic Committee (IOC) worried with attendees at a summit earlier this month voicing "serious concerns" over the proposals and its impact on the world sporting calendar.
"Why are the Olympic Games every four years? Because it's an event that you have to look forward (to), that you have to wait (for), and you have to enjoy it," Ceferin added.
"And it's the biggest football event - it has to be every four years. But it's very clear - 75% of fans around the world reject the idea (of a biennial World Cup)."
FIFA boss, Gianni Infantino, on continuing his push for a biennial World Cup, said in a new year message that "FIFA is the only governing body that looks after and cares about the entire world".
He continued: "We will continue working hard to live up to the mission of not forgetting the ones who need most and who have no voice, while also protecting the healthy growth of everyone else and the global football movement.
"The new FIFA is a democratic body and together with our stakeholders, we will design the path for football's future, making the game fit for purpose in the modern era and ensuring that we can boost global competitiveness."
Infantino said after the global summit earlier this month that he believed a majority of national associations would already be in favour of biennial World Cups if the idea was put to a vote, but said it was important that the entire shape of the calendar be looked at rather than just one element of it in isolation.
"We count on the vast majority who are looking forward to new exciting opportunities to dream, to develop the game, to feel truly part of the global football community," Infantino added in Thursday's message.
"And we count also on those at the top to show solidarity - without which, even football at its most elite would not exist.
"We thank them for their valuable contribution to the popularity of the game and we count on their support, respect and strategic vision as we strive to successfully conclude the discussions around reform of the international match calendar.
"We will work together for unity and the ultimate benefit of everyone."