Mexican leftist faces test in capital vote march

MEXICO CITY (Reuters) - The leftist claiming fraud in Mexico's presidential election two weeks ago faces a test of his strength on Sunday when he heads a huge rally through the capital in support of his call for a vote recount.

Andres Manuel Lopez Obrador, who pulled a crowd of 100,000 protesters last weekend, hopes for an even bigger demonstration of support at a march through the city's main Reforma avenue.

Lopez Obrador, 52, is trying to put pressure on an election court that will rule on his charge that conservative Felipe Calderon, the government and electoral officials stole the presidency from him through fraud.

Calderon came from behind in opinion polls to win the July 2 election by a fraction of a percentage point. The court must rule by early September on who actually won the vote, which split the nation between right and left only six years after President Vicente Fox ended 71 years of single-party rule.

Officials from Lopez Obrador's Party of the Democratic Revolution have told the Mexican media they expect up to half a million people on the march.

Protesters will walk past the U.S. Embassy, international hotels and a business district before holding a mass rally in the Zocalo square, once the center of the Aztec world and now home to the National Palace seat of government and the city's Spanish colonial cathedral.

The square, one of the largest in the world, has become the focus of protests to back Lopez Obrador, who was the capital's popular mayor until quitting last year to run for president.

"We'll move in and live here if need be," said leftist Juan Carlos Escandon, gathering signatures in favor of Lopez Obrador in the Zocalo.