European football leaders on Tuesday backed the move by FIFA vice president Prince Ali bin Al Hussein to challenge Sepp Blatter for the presidency of football's scandal-tainted world body.
The 39-year-old Jordanian royal said he would seek to end "controversy" when he tries to stop Blatter securing a fifth term in the FIFA election on May 29.
Prince Ali is an ally of UEFA president Michel Platini, an outspoken critic of Blatter's move to extend his rule.
The prince is certain to get nearly all the 54 European votes in the election, but will face a tough battle to get the 105 votes needed from FIFA's 209 member federations.
"I know Prince Ali well. He has all the credibility required to hold office," said Platini, signalling his approval.
"We now await his proposals and his programme for the future of football."
English Football Association chairman Greg Dyke also welcomed the prince's decision. The FA have been a leading European critic of Blatter.
"It is very important that there is a credible candidate standing against Mr Blatter and Prince Ali is certainly that."
The prince, a FIFA vice president for Asia since 2011, said he was entering the contest because "it is time to shift the focus away from administrative controversy and back to sport." He added that he had acted after talks with top FIFA personalities.
"The headlines should be about football, the beautiful sport, not about FIFA," he said.
The ruling body has been dogged by scandal since 2010 votes that awarded the 2018 World Cup to Russia and 2022 event to Qatar.
"This was not an easy decision. It came after careful consideration and many discussions with respected FIFA colleagues over the last few months," Prince Ali said.
"The message I heard, over and over, was that it is time for a change."
He said FIFA should be "a model of ethics, transparency and good governance."
Prince Ali, a son of the late King Hussein, was one of the most senior FIFA officials to call for the full publication of lawyer Michael Garcia's report into the 2018 and 2022 World Cup bids.
FIFA's executive has voted to release an "appropriate" edited version of the report and Blatter has ruled out any suggestion that Qatar could lose the right to host the 2022 tournament.
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UEFA's Platini and European federations have led calls for Blatter to keep an earlier promise to stand down when his fourth term ends.
But the 78-year-old Swiss official says he has a "mission" to finish.
- FIFA lobbying battle -
Blatter has long been a controversial figure, and FIFA, which oversees a multi-billion dollar industry, has never been far from scandal.
Prince Ali is FIFA vice president for Asia, head of Jordan's Football Association and founder of the West Asian Football Federation.
He will need five FIFA federations to nominate him before a January 29 deadline. But UEFA's backing should make this a formality.
He will step up lobbying for Asian support at a special Asian Football Confederation congress in Melbourne, Australia on Friday.
Prince Ali is in a battle for influence with AFC head Bahrain's Sheik Salman bin Ibrahim Al Khalifa, who has publicly supported Blatter's campaign for a new term.
Africa's 54 members have pledged their support for Blatter.
Europe and Asia account for about 100 members of FIFA, meaning that the prince and Blatter will be fiercely lobbying North and South American nations as well.
The only other declared candidate in the race is Jerome Champagne, a French former FIFA official and diplomat.
He said the election should not be "about personal ambitions or fights between institutions.
"It is about football, its governance, but also its future with a clear choice."
He said there could be "continued inner rivalries and image problems for FIFA and football. Or reconciliation, inclusion and re-building of the reputation."
Blatter made no immediate comment on the candidacy of Prince Ali, a major general in Jordan's armed forces who was educated in the United States and Britain.