"I do not think that this is going to be a close race. I think we can win by more than one million votes... This government will not have a hard time acknowledging its defeat," Capriles, 40, told foreign media at a press briefing.

"The only polls that have not changed are the ones that the government paid for," Capriles charged, claiming one poll gave him a lead.

Hundreds of thousands of backers of opposition candidate Capriles thronged the streets in Venezuela's capital on Sunday, echoing his rising threat to Chavez's re-election.

Socialist-populist Chavez, 58, has been in power since 1999, and is seeking reelection. Former governor Capriles, 40, is a center-left pragmatist who says his model is Brazil's former president Luiz Inacio Lula da Silva.

The latest opinion poll gives the incumbent a 10-point advantage over Capriles, but the challenger has cut the lead by half in just four months.

Chavez was favored by 49.4 percent of voters, compared to 39 percent for Capriles in a poll released this week by Datanalisis. A significant number of voters, 11.6 percent, remain undecided.

Other polls gave Chavez a bigger lead, while some found a statistical tie.