Radical Mexican leftist claims party leadership win

By Miguel Angel Gutierrez and Catherine Bremer

MEXICO CITY (Reuters) - A leftist firebrand who narrowly lost Mexico's 2006 presidential election took a step toward a political comeback on Monday when a close ally claimed victory in the main opposition party's leadership race.

Leftist Andres Manuel Lopez Obrador's candidate Alejandro Encinas declared himself the victor and initial results gave him a lead of more than 3 percentage points in Sunday's vote to lead the Party of the Democratic Revolution, or PRD.

Encinas, former mayor of Mexico City, vowed the party would continue refusing to recognize the government of conservative President Felipe Calderon, who defeated Encinas's mentor Lopez Obrador in an election leftists say was tainted by fraud.

His election win would bolster a new campaign of street protests by Lopez Obrador -- who jammed Mexico City with sit-in camps after the 2006 election -- against government proposals to allow private partnerships in the state-run oil sector.

"We will be firm defending our ideals through peaceful civil resistance," Encinas said.

A PRD spokesman said preliminary results with 35 percent of polling stations counted gave Encinas 43.98 percent against 40.60 percent for moderate rival Jesus Ortega, in line with exit polls. The final result is due on Wednesday.

Encinas's victory will be read as proof of strong party support for Lopez Obrador, who calls himself Mexico's "legitimate president" despite an election tribunal confirming Calderon's election win by less than 1 percentage point.

It will set the party on a more radical path ahead of 2009 congressional elections, and raises the chances of Lopez Obrador having another shot at the presidency in 2012.