By Manny Mogato
MANILA (Reuters) - A seven-term Philippine mayor who has built a reputation fighting crime, plunged into the presidential race on Monday, a surprise move that could shake up the election, analysts said.
Rodrigo Duterte, a 70-year-old lawyer, better known as the "the Punisher" for dealing with criminals in southern Davao City, vowed to clean up politics in one of Asia's most graft-ridden countries.
"Yes, I am running," Duterte told reporters in Manila after holding off on appeals by his supporters for weeks to join the race to succeed President Benigno Aquino next May.
The election is being closely watched by investors who fear the political succession in one of Asia's fastest growing economies could derail gains made during Aquino's rule.
Grace Poe, a senator who was abandoned as a baby, is leading the race, surveys showed. Vice President Jejomar Binay is running second while Aquino's choice as successor, former interior minister Manuel Roxas, is in third place, the latest poll showed last week.
Duterte said he decided to run for president to stop Poe from becoming one, saying she wasn't a natural-born Filipino and therefore ineligible to take the highest job in the country.
Poe, the adopted daughter of a late popular movie action hero, last week defeated a legal bid to unseat her from the Senate, boosting her chance to win other cases seeking to block her presidential run.
But Duterte said the election tribunal had overstepped its authority in giving that decision.
"We Filipinos belong to different tribes but a piece of paper called the constitution holds us together," he said. "We should respect the constitution. The election tribunal has set aside the constitution to favour Poe."
Under Aquino, the Philippines has seen economic growth of more than 6 percent on average, its best 5-year record in four decades. He has also battled to rein in corruption.
Duterte missed an Oct. 16 deadline to register his candidacy but the rules allow him to stand as a replacement candidate by December when the election authorities start printing ballot papers.
Political analyst Ramon Casiple said Duterte's anti-crime crusade resonates among poor Filipinos, bringing drama to the election next May.
"He's a threat to everybody," he said. "It's an entirely new ballgame with Duterte joining the fray."