FIFA President Gianni Infantino, center, and CONCACAF President Victor Montagliani attend the 2026 World Cup football tournament quarter-final match between Norway and England at Miami Stadium in Miami on July 11. AFP-Yonhap

A senior adviser to FIFA President Gianni Infantino resigned in protest at plans to sell a stake in the World Cup on Friday, as European football threatened a boycott and regional confederations united in opposition to the controversial proposal.

Carlos Cordeiro resigned with immediate effect, calling the plan "a bad deal for football".

Cordeiro, who was appointed in 2021 by Infantino to help shape FIFA's future, said the body was "mortgaging football's future without any compelling justification".

"It is a bad deal for FIFA's Member Associations, a bad deal for football, and a bad deal for the long-term future of the game," Cordeiro said in a statement.