The controversy and confusion surrounding Mexico's presidential election deepened Tuesday as electoral officials released new results that further tightened the razor-thin gap between left-of-center candidate Andres Manuel Lopez Obrador and front-running conservative Felipe Calderon.

Supporters of Andres Manuel Lopez Obrador of the PRD protest Tuesday against alleged irregularities in Sunday's presidential elections outside of Lopez Obrador's Mexico City headquarters. (Associated Press photo by Eduardo Verdugo)

Campaign officials for Lopez Obrador demanded a full recount, insisting that the official preliminary results, which had been released hours after the Sunday voting, were plagued by errors and that their candidate had won the election.

Federal Electoral Institute officials were under mounting public criticism Tuesday for not counting some 2.6 million ballots that they deemed had "inconsistencies" because of conflicting information or blank entries. At a hastily called evening news conference, institute officials finally released these votes, which narrowed Calderon's lead from 1.04 percent to 0.64 percent.

Election officials also noted that the initial count did not include an additional 827,317 ballots that were nullified because of undisclosed errors or approximately 800,000 ballots that did not arrive to counting centers on time.

With Calderon now leading by only 257,532 votes out of more than 41 million cast, Mexico seems poised for an acrimonious, drawn-out post-electoral struggle strikingly similar to the Florida recount in the 2000 U.S. presidential race.

Government and political party officials say the overall process, together with court appeals, could drag on for days, weeks or even months, although nobody seemed quite sure how all the complicated electoral and legal machinery would unfold.

The elections institute is scheduled to begin a final count today at 300 district offices across the country, where the polling-place summary reports will be read aloud before representatives of all political parties. The final tally is expected to be announced no later than Sunday.

It is unclear whether the Lopez Obrador campaign's demand for a ballot-by-ballot recount will be met.

"We are convinced of the victory of our candidate," said Lopez Obrador's campaign manager, Jesus Ortega. "We demand a recount vote by vote, report by report, polling station by polling station."

Calderon campaign officials downplayed the demand.

"In this election, Calderon is leading and that will be confirmed when the counting by all the election boards is finished," said German Martinez, representative of Calderon's National Action Party, or PAN.

The administration of President Vicente Fox, who also belongs to the PAN, jumped into the fray by trying to quash the request. Interior Secretary Carlos Abascal said recounting every ballot was "physically impossible and also legally impossible." However, Abascal has no authority over electoral issues, which are in the hands of the autonomous electoral institute.

Luis Carlos Ugalde, the institute's president, did not reject the recount request but made a not-so-veiled warning to Lopez Obrador: "For the good of democracy, the (institute) emphatically implores the political parties to behave responsibly," Ugalde told a news conference Tuesday night.

The fast-moving electoral controversy appears to be driven as much by Lopez Obrador's grassroots supporters as by the candidate himself, and it has illustrated the emerging power of Mexico's bloggers.

On Monday morning, Lopez Obrador had stated meekly in public that he would accept defeat if announced by the Federal Electoral Institute. That appearance, in which his haggard face seemed depressed and defeated, detonated a whirlwind of Internet organizing. Within hours, his supporters had deluged the headquarters of Lopez Obrador's Democratic Revolution Party, or PRD, with e-mails alleging inconsistencies in the vote counting and reporting process.

PRD bloggers furiously gathered allegations about fraud and distributed instructions on how to report problems to the PRD campaign and how to contact the media. By Monday night, Lopez Obrador had emerged again and announced that his party's lawyers would lodge legal appeals with the electoral institute's independent tribunal. He cited several photos of apparently contrasting poll booth count documents that had been sent to him, and he repeatedly asked his followers to keep up the e-mail barrage.

"In the meantime, we are going to ask, or keep asking, the citizens to keep helping us find many inconsistencies," said Lopez Obrador.

The Lopez Obrador campaign also made it clear that they were preparing a complex, Florida-style legal challenge. Party officials said they were busy printing 5 million flyers declaring their man to be Mexico's next president and calling for organized protests.

However, some PRD officials seemed nervous about unleashing the grassroots anger of their supporters, who in past years have been well known for their sit-ins, highway blockades and other forms of raucous civil disobedience.

The PRD's mayor-elect of Mexico City, Marcelo Ebrard, tried to dissuade organizers from carrying out a protest march through downtown scheduled for today.

"This isn't convenient for us at this moment," he said. "We don't want to fall into the trap of rejecting the whole electoral process."

©2006 San Francisco Chronicle

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