The other candidate has vowed to block his opponent from taking power.
MEXICO CITY -- The nation's top electoral court declared conservative candidate Felipe Calderon president-elect Tuesday, but the decision is unlikely to resolve a political crisis sparked by the muddled outcome of the July 2 contest.
The ruling approved unanimously by the seven judges of the Federal Electoral Tribunal is final and cannot be appealed. But losing leftist candidate Andres Manuel Lopez Obrador is vowing to lead a parallel leftist government from the streets.
Lopez Obrador, whose support is dwindling but becoming more radical, said he will not recognize the new government.
"I do not recognize someone who tries to act as the chief federal executive without having legitimate and democratic representation," Lopez Obrador told followers at Mexico's main central plaza, the Zocalo.
The final tally released by the court Tuesday showed that Calderon defeated Lopez Obrador by 233,831 votes out of 41 million cast, or 0.56 of a percentage point.
Lopez Obrador has vowed to block Calderon from taking power Dec. 1. Protesters outside the tribunal wept as the decision was announced and set off firecrackers that shook the building.
"We aren't going to let him govern!" Thomas Jimenez, a 30-year-old law student, screamed as hundreds of protesters threw eggs and trash at the courthouse.
A 44-year-old stalwart of the National Action Party, or PAN, Calderon was virtually unknown to most Mexicans just two years ago. He is a former congressman and was energy secretary under Fox.
No Mexican president has ever assumed office with a smaller electoral mandate -- Calderon won just 35.7 percent of the vote. A poll this week by the newspaper El Universal found that 39 percent of Mexicans believe the election was stolen from Lopez Obrador.
Tribunal Magistrate Alfonsina Navarro Hidalgo said Tuesday that the many irregularities cited by Lopez Obrador in his complaint were of a minor nature and did not rise to the legal standard needed to overturn the result.
"There are no perfect elections," she said. "To think otherwise is a utopia." Magistrate Eloy Fuentes Cerda added: "The winner of the election is the candidate who wins the most votes, no matter how small the margin."
Last week, the court found Lopez Obrador's charges of massive fraud unfounded.
Critical of Fox
Judges were critical Tuesday of President Fox, whose public-service spots on behalf of his party's candidate were ordered off the air on the grounds that they violated election laws that limit what incumbent presidents can do and say to help ruling party candidates.