FIFA Vice President Prince Ali bin Al Hussein on Tuesday threw down the gauntlet to incumbent Sepp Blatter for the leadership of football's scandal-tainted world governing body.
The 39-year-old Jordanian prince said he would be a candidate against Blatter, 78, who will seek a fifth term, when FIFA holds a presidential vote on May 29.
Prince Ali, an ally of Blatter rival Michel Platini, the UEFA president, said he had been encouraged by other FIFA members to stand.
He is guaranteed nearly all the 54 UEFA votes and must now aim to sway enough FIFA members from his Asia region and other confederations against Blatter to get 105 backers at the election.
The rivalry threatens to become bitter.
The prince said his campaign would be based on getting FIFA away from "contoversy".
"I am seeking the presidency of FIFA because I believe it is time to shift the focus away from administrative controversy and back to sport.
"The headlines should be about football, the beautiful sport, not about FIFA."
FIFA has been dogged by scandal since 2010 votes that awarded the 2018 World Cup to Russia and 2022 event to Qatar. The prince, a FIFA vice president for Asia since 2011, has been among leaders who want the full release of an inquiry into the vote process.
"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.
"The world game deserves a world-class governing body -- an International Federation that is a service organisation and a model of ethics, transparency and good governance."
Prince Ali, a son of the late King Hussein of Jordan, 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.
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.
The prince will need five of FIFA's 209 member 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.
"FIFA exists to serve a sport which unites billions of people from all over the world, people of differing and divergent political, religious and social affiliations, who come together in their enjoyment of 'the world's game'," the prince said.
The only other declared candidate in the race is Jerome Champagne, a French former FIFA offiical 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."
The FIFA leader 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.