Football Association chairman Greg Dyke said the governing body will drop its backing for Michel Platini if FIFA's ethics committee finds he behaved improperly.
UEFA president Platini and FIFA president Sepp Blatter have been handed 90-day provisional bans by the committee while investigations take place into a ?1.35million payment to the Frenchman.
The action leaves Platini's hopes of running to succeed Blatter in tatters. An FA statement merely said it was waiting for the outcome of the investigation - but Dyke said it is prepared to drop its support.
Dyke told Press Association Sport: "If the ethics committee reaches a conclusion that Mr Platini has not behaved properly or has behaved dishonestly then of course the FA will not support him.
"That's why we said in our statement that we are awaiting the results of the investigation - we need to see the evidence.
"I can see why people are saying we should stop supporting him now, but we will follow what the ethics committee decides.
"Platini claims it's a fix, but if they decide he has behaved improperly we will not support him and I'm sure I would have the backing of the FA board on that.''
Dyke added that if there was any finding of wrongdoing by the investigations into the bids for the 2018 and 2022 World Cups he was convinced there would have to be a re-vote.
"I have no doubt if the evidence comes out that a bid was won by corruption there will have to be a re-vote,'' Dyke said.
Dyke will give evidence to MPs on the FA's backing for Platini at a parliamentary hearing in two weeks' time.
FIFA sponsors, the Serious Fraud Office and Domenico Scala, the head of FIFA's independent audit and compliance committee are also due to appear at a two-day meeting of the Culture, Media and Sport select committee.
FIFA moved to relieve Blatter of his duties immediately after his provisional ban was announced - but by contrast Europe's ruling body said it was standing by Platini, though he is complying with the ban.
If that defiance escalates it would further destabilise the world governing body, which is already in meltdown following the suspensions announced against Platini, Blatter and FIFA secretary general Jerome Valcke.
UEFA's executive committee said on Thursday night it had "full confidence'' in Platini and would not be replacing him as president. A statement from Platini was also released through UEFA, an action which appears to be at odds with the terms of his ban.
Platini said: "I reject all of the allegations that have been made against me, which are based on mere semblances and are astonishingly vague. Despite the farcical nature of these events, I refuse to believe that this is a political decision taken in haste in order to taint a lifelong devotee of the game or crush my candidacy for the FIFA presidency.
"I want everyone to know my state of mind: more than a sense of injustice or a desire for revenge, I am driven by a profound feeling of staunch defiance.''
UEFA said Platini "will not perform his official duties for the time being''.
He did not attend the meeting of the UEFA executive committee on Thursday and has cancelled several official trips.