Updated

After weeks of closed-door deliberations that will determine Mexico's next leader, the nation's top electoral court on Friday prepared to hold its first open session on the country's disputed presidential race.

The session, scheduled to begin Saturday morning, will give this divided nation its first look at how the Federal Electoral Tribunal plans to deal with Andres Manuel Lopez Obrador's allegations of widespread fraud and dirty campaign practices in the July 2 election.

CountryWatch: Mexico

The leftist Lopez Obrador is demanding a full ballot-by-ballot recount, which he says will show he won the race. An official count, still uncertified by the court, gave ruling party candidate Felipe Calderon an advantage of less than 0.6 percent, or about 240,000 votes.

The tribunal has until Sept. 6 to declare a president-elect or annul the elections entirely.

The seven judges will begin by ruling on 174 allegations of fraud, filed by Lopez Obrador's lawyers. Those rulings will likely determine whether they will order a full or partial recount.

Gerardo Fernandez, a spokesman for Lopez Obrador's Democratic Revolution Party, said he expects the court to decide before Monday on the recount request, and that party officials have no idea how the court would rule.

While Mexican election law allows for limited vote-by-vote recounts when there is evidence of irregularities involving specific polling places, Fernandez said that only a full recount of the more than 41 million votes cast can put an end to widespread allegations of fraud and questions about the country's electoral system.

Representatives for Calderon were not immediately available for comment Friday, but the conservative candidate has called the elections clean and fair, and argued that a full recount would violate Mexican law.

Lopez Obrador's party won a small victory late Monday when the tribunal voted unanimously to consider a possible recount.

But it dealt an apparent blow to the candidate's "shotgun" strategy of citing thousands of irregularities at the 130,000 polling places, saying it would not roll all the legal challenges into a single case, but would consider each on its own merits.

The race was the closest presidential contest in Mexican history — Calderon's lead amounts to less than two votes per polling place — reflecting a nation sharply divided along class and social lines.

Lopez Obrador has promised to govern for the poor, while Calderon has the backing of the nation's growing middle and elite classes, many of whom want to protect the new homes and cars they have been able to purchase with falling interest rates.

Supporters of Lopez Obrador have seized control of the city's cultural and financial heart, setting up protest camps on the elegant Reforma Avenue and in the city's main Zocalo plaza and snarling traffic for nearly a week. Braving nearly nightly rainstorms and even flooding, they say they won't leave until the tribunal rules on their demands.

Protester Maria Elena de Mesa Sanchez, a 59-year-old preschool teacher, cautiously welcomed Saturday's public session, but complained about the court's "slowness, given the national unrest caused by the election's irregularities."

Many have begun to question Mexico's electoral system, held up to the world as a model for emerging democracies after President Vicente Fox's historic victory in 2000 ended 71 years of one-party rule. Electoral officials have defended their work, and most election observers said the vote was fair.

But de Mesa isn't convinced.

"I hope that they don't let me down," she said of the tribunal's seven judges. "I'm waiting for a response that will satisfy the people."

Also Friday, a Lopez Obrador supporter interrupted a speech by President Vicente Fox in a slum on Mexico City's outskirts, by holding up a sign calling for a recount. As many yelled for the protester to be removed, Fox said: "Leave him alone, and let him enjoy this country's freedom of expression.