World heavyweight champion Vitali Klitschko will run for president in his native Ukraine in 2015.
Klitschko, 42, holds the WBC belt. He had been the subject of attempts to prevent him from standing because of his residency rights in Germany.
He is head of the Ukrainian Democratic Alliance for Reform political party.
He stated his intention to the country's parliament on Thursday.
"Everything that has taken place in parliament today with texts of laws, directly backed by ruling party deputies, does not intimidate me and will not stop me," Klitschko said.
"To head off these various schemes and attempts at getting even with me as a possible candidate, I want to declare this: I will run for president."
Klitschko has not fought since a victory over Manuel Charr of Germany in Moscow in September 2012.
His brother, Wladimir Klitschko, holds the WBA and IBF heavyweight titles. He defeated Russia's Alexander Povetkin in a title defense earlier this month.