Mexico City, Jan 31 - Tens of thousands of demonstrators marched through Mexico's capital on Wednesday night to protest a surge in tortilla prices that has put President Felipe Calderon under intense pressure.
Soaring U.S. demand for ethanol has sent corn prices to their highest level in a decade, pulling up prices of Mexico's national food staple.
Protesters held up ears of corn and complained that Calderon, a conservative accused by leftists of stealing the July 2006 presidential election, was failing to protect them against foreign market forces.
"Calderon isn't just a thief, he's a murderer because he wants us to die of hunger," Elvira Acevedo, 62, said at the march.
Calderon's leftist election rival, Andres Manuel Lopez Obrador, is using the surge in tortilla prices to snipe at the government and he joined the protest march on Wednesday.
"The right dehumanizes everything. We are living the consequences of the imposition of a government dominated by white-collar criminals. They are a danger to Mexico," the firebrand former Indian rights activist told supporters in the vast Zocalo square.
Corn tortilla prices rose as high as 15 pesos ($1.36) for a kilogram (2.2 pounds) -- roughly 35 of the flat corn patties -- in recent weeks as the corn market tightened. Mexico imports corn from the United States to top up its domestic production.
Calderon responded this month by persuading producers, makers and retailers to cap their prices so tortillas would sell at no more than 8.50 pesos a kilogram, but local media say some vendors are still charging up to 12.
Before the crisis, tortillas sold at around 5 pesos per kilogram.
Calderon has won praise at home and abroad for sending out thousands of troops to hunt down drug cartels since he took office on Dec. 1, but what is being dubbed a "tortilla crisis" for the half of Mexico that lives on $5 a day or less is stealing headlines.
Lopez Obrador held massive street protests that crippled Mexico City after the fiercely contested presidential election but Mexico's top election court threw out his fraud allegations were thrown out and Calderon was able to take office.