Updated

Mexico's leftist party demanded Tuesday that electoral officials recount each and every vote cast in the nation's presidential race.

The demand by Andres Manuel Lopez Obrador's campaign manager Jesus Ortega renewed fears that the Democratic Revolution Party's fiery candidate will mobilize millions of supporters and launch massive street protests if he doesn't get his way.

Lopez Obrador's supporters claim the preliminary vote count showing business-friendly rival Felipe Calderon with an advantage of about 400,000 votes was manipulated.

CountryWatch: Mexico

The official vote count by the autonomos Federal Electoral Institute starts Wednesday and could take days. Even if a winner is declared, those results can be challenged in court.

The fiscally conservative Calderon's apparent win caused financial markets and the peso to rally for a second day Tuesday. The former energy secretary, representing President Vicente Fox's National Action Party, told Radio Formula that "the people are right, the markets are right" in assuming he has won.

Mexico must now focus on the future, he said in an interview with Radio Formula. "The problems are big, but Mexico is bigger than its problems," he said.

There were some fears that Lopez Obrador's refusal to accept Calderon's apparent victory could throw the country into turmoil. Allegations of irregularities threaten to drag out the process for weeks, if not months, putting Mexico's young democracy to the test.

Tensions were rising Tuesday in southern Oaxaca state, where striking teachers occupied businesses, boarded buses and blocked roads despite pledges to halt their sometimes violent campaign until the presidency had been decided.

Speaking to reporters at his campaign headquarters Monday night, Lopez Obrador said "There are about 3 million votes missing."

The former Mexico City mayor explained that officials had estimated a voter turnout of about 41 million or 42 million, yet preliminary vote tallies by the electoral institute only showed about 38 million ballots cast.

As a result, the institute's first count is something that "we cannot accept," he said.

Both candidates declared victory Sunday night. Representatives of Roberto Madrazo, of the Institutional Revolutionary Party, or PRI, conceded the race Monday night.

Lopez Obrador continued to claim victory, saying, "we have a commitment to the citizens to defend the will of millions of Mexicans."

"We are going to employ whatever legal means," he told supporters.

He claimed there were "many irregularities" in the election, including badly reported results and the double counting of votes. He also asked how it was possible that his party won 155 of 300 electoral districts without winning the presidency.

In an interview Tuesday with the Televisa network, Luis Carlos Ugalde, the electoral institue's president, said officials would review any problems during the official count.

With 98.45 percent of polling stations reporting, Calderon had 36.38 percent and Lopez Obrador had 35.34 percent. Madrazo was a distant third with 21.57 percent, and minor candidates and write-ins accounted for the rest.