By Andrew Cawthorne and Eyanir Chinea
CARACAS (Reuters) - Venezuela's President Hugo Chavez boasted on Tuesday he had a "mathematically irreversible" lead ahead of next month's vote and that a refinery disaster had not damaged his re-election campaign as some forecast.
The 58-year-old socialist leader had a tough month in August: The blast at Amuay refinery killed 42 people in Venezuela's worst oil industry accident; steel workers heckled him at a rally; and there was fury and road chaos when a major bridge collapsed.
Yet the majority of Venezuela's traditional pollsters still give him a healthy two-digit lead ahead of the October 7 ballot, thanks to enduring popularity among the poor, a national economic uptick and heavy spending on welfare projects in slums.
"Many in the right-wing sectors rubbed their hands at the Amuay tragedy, thinking it was going to affect us and be the event that turned the table," Chavez said, adding two new unpublished polls saw his lead grow since the August 25 disaster at the Amuay oil refinery.
Chavez traveled quickly to the disaster site in western Venezuela, supervising the rescue operation and offering new homes to victims. But he was pilloried by critics, including opposition candidate Henrique Capriles, for neglect and mismanagement of the OPEC member's oil industry.
Chavez said one new survey showed his lead over Capriles growing from 12 to 14 percent. "That's what they call mathematically irreversible," Chavez told a local radio station. "The gap, according to this poll, whose owner is very friendly with the candidate of the right ... the gap actually widened."
Another, he said, gave him a 20 percentage point lead. There was no independent confirmation of either.
Opinion polls vary widely in Venezuela, and are a highly controversial subject, with both sides accusing the other of having favored pollsters linked to them.
Capriles, a 40-year-old state governor who hails Brazil's "modern left" model as his inspiration, is running an energetic campaign based on visits to hundreds of villages and towns around the nation, especially in remote and pro-Chavez areas.
"Don't believe the bogus polls," Capriles told Reuters on a recent campaign trip, pointing to several surveys that bucked the general trend and showed him neck-and-neck with Chavez.
"I expect to win by about 10 points."
Having failed to dislodge Chavez via the ballot box, national strikes, mass street demonstrations and even a short-lived military uprising, opponents have united in a coalition behind Capriles and believe they have their best chance yet.
Opposition activists say Capriles' grassroots campaign will bear fruit in the final weeks of the election race, while government employees' fear of expressing their true intentions were skewing some surveys.
With Venezuela's 29 million people deeply polarized between "Chavistas" and opponents, predictions by some analysts of a violent election campaign have not materialized though there have been some isolated incidents of shootings and scuffles.
The government's arrest order for a pro-opposition TV station cameraman over an alleged shooting, and the election board's prohibition of two opposition publicity spots, have stirred passions in recent days with just over a month to go.
Remarkably, Chavez's health - which dominated headlines from Venezuela until recently - has taken a back seat in the campaign over the last month.
After three operations and lengthy treatment in Cuba for an undisclosed cancer over the previous year, Chavez declared himself completely cured in July. He has demonstrated an upsurge in energy since, enabling him to attend some outdoor rallies and pop up on state media almost daily.
In his comments on Tuesday, Chavez said he had feared at one point he might have to give up his political career, adding that the health scare had deepened his Christian faith.
"Thank God, I am recovered," he said, demonstrating his good mood in a sing-along with his interviewers.
"I feel really well."
Doctors, however, warn that nobody can proclaim themselves cured from cancer until at least a couple of years have passed since the last recurrence, meaning that Chavez's health will remain a wildcard factor going forward.
The stakes are high at the October 7 vote not only for Venezuela, which has the largest oil reserves in the world, but also for the wider region.
Political allies from Cuba to Bolivia depend on Chavez's oil-financed largesse. Washington, too, is watching quietly to see if its fiercest critic in Latin America wins an election that would potentially extend his rule to 20 years.
(Editing by Brian Ellsworth and Cynthia Osterman)