Visa, Emirates, Coca-Cola and adidas have expressed concern over allegations of corruption at the top level of the game's administration.

Income from the key sponsors amounts to 26% of FIFA's revenue, around US dollars 1billion, giving them an influential voice within the organisation

Harry Karaolou, sports lawyer at City law firm Lawrence Graham, believes they may yet dictate what changes, if any, take place at FIFA.

"An important factor to consider is the weight of the corporate sponsors, who have been relatively quiet so far," said Karaolou.

"If the FIFA brand is tarnished, even if the allegations are proved to be untrue, the lack of transparency and the body's stubbornness to change will put major brands in a very difficult position.

"They will not allow their reputation to be damaged by association - many will simply walk away and will have a clause in their contracts enabling them to do so without penalty.

"This is a common clause sponsors rely on when individual sport stars find themselves on the front rather than back pages.

"I suspect that the corporate sponsors, who are the lifeblood of FIFA, will ultimately have the deciding vote in what happens to the organisation."

Karaolou also stressed that any protest withdrawal by the Football Association and Scottish Football Association would have far-reaching consequences for the game in this country.

"If the FA and SFA increased the pressure on FIFA by withdrawing from the organisation there would be no UK participation in the World Cup or European Championship," he said.

"It could even transpire that no overseas players would be able to play in the English leagues as they would not be recognised by FIFA."