Oil exploration issue splits Mexico

The debate over "energy reform" has split Mexico's political class, with the left threatening national civil disobedience to stop Congress from considering it and a key centrist ally of Calderon withdrawing its support.

Pemex, short for Petroleos Mexicanos, says that it needs outside technological help to bring up oil from deep-water fields. But such a proposal raises the hot-button question of whether foreign companies should be allowed to invest and profit from any of Mexico's oil riches.

The issue is deeply emotional as well as politically charged. Mexico nationalized its oil fields in 1938, expropriating American and European companies. Ever since, most Mexicans have considered public ownership of the country's most lucrative natural resource to be a cornerstone of their sovereignty.

On Tuesday, leaders of the leftist Democratic Revolution Party, or PRD, announced that they would form "resistance brigades" composed of 10,000 women and 18,000 men to fight Calderon's proposals with marches and barricades.

And Wednesday, leaders of the Institutional Revolutionary Party, or PRI, expressed opposition to key elements of the reforms, though they earlier had suggested that they might support it. Calderon needs PRI votes to pass any legislation.

"We are in complete disagreement with the [Calderon] government," Manlio Fabio Beltrones, a PRI senator, said in a radio interview.

Analysts say Mexico's oil reserves could be depleted in a decade if new fields aren't discovered and tapped.

The county's main oil field, Cantarell, is in a major decline. In February, the output of Cantarell, in shallow Gulf of Mexico waters off Campeche state, averaged 1.145 million barrels per day, according to government figures. That's off 24% compared with to the same month last year. And it's down 46% since production peaked at just over 2.1 million barrels per day in 2004.

Calderon has said that Pemex needs foreign help to explore new fields.

In an interview with The Times in February, Calderon suggested that Mexicans should not look upon foreign investment in the oil industry with fear. He pointed to China and Brazil, two countries with government-controlled oil companies that allow foreign investment.