By Daniel Wallis
CARACAS (Reuters) - Venezuela's Hugo Chavez is due to begin radiation treatment on Sunday in Cuba, where he also could meet Pope Benedict in the latest high profile development as the president tries to fight off cancer and win re-election.
Chavez is returning to Havana a month after he had surgery there to remove a second malignant tumor from his pelvis. The treatment will take him off the political stage just as his election rival gears up a nationwide campaign tour ahead of the October 7 vote.
The return of the socialist leader to the Communist-led island coincides with a rare visit to Cuba by the pope, and Venezuelans have been captivated by the possibility that Chavez, who says he has gained a new spiritual outlook on life since his illness, could have a private audience with him there.
Nelson Bocaranda, a pro-opposition Venezuelan journalist who has broken news on the president's cancer treatment in the absence of much official information, said his sources in Cuba and the Curia, the central governing body of the Roman Catholic church, told him the pope had agreed to meet Chavez.
"The meeting will be strictly private, without media coverage, and the only ones who will be present, in addition to the pope and Chavez, could be the Castros and the Venezuelan's daughters," Bocaranda wrote in his column on Sunday.
"No other relatives nor Venezuelan officials can be at the meeting, which took so much to organize. No representative of the Venezuelan bishops will be present in Cuba."
Bocaranda said his sources told him the Vatican's secretary of state, Cardinal Tarcisio Bertone, also could attend the talks, which were likely to be held at the Palace of the Revolution in Havana. Pope Benedict is ending a three-day tour of Mexico and is due to arrive in Cuba on Monday.
Little is known about what kind of cancer Chavez has, nor how serious it is, so big questions remain about his future.
His latest departure from Venezuela will stoke anxiety among supporters worried about his health, as well as fan persistent rumors of a nascent power struggle among his inner circle.
After three cancer operations in less than a year and four sessions of chemotherapy treatment, Chavez says he has been spiritually "reborn." He frequently invokes God and the spirits of the Venezuelan plains where he was born.
Chavez has dominated the nation's politics for the past 13 years and his illness has shocked voters across South America's biggest oil exporter in the run-up to the election.
CHAVEZ TO RETURN HOME 'IN DAYS'
Some question how fit he would be to govern if he won and the radiation therapy is expected to keep him from conducting the kind of man-on-the-street campaign that has worked so well in the past to help him drive forward his leftist "revolution."
On Saturday, Chavez said the treatment would last four to five weeks but that he would return to Venezuela in a few days.
"You must know that radiation therapy lasts several days, then a break, then more days, then another break, so I'm going to be coming and going," he said. "It's possible that we could do some sessions in Venezuela.
"The most important thing, whether it's here or there, is the effectiveness of the treatment."
Chavez's weaker figure contrasts sharply with the energetic image presented by his rival, basketball-loving 39-year-old Miranda state governor Henrique Capriles.
But most recent polls have given Chavez a strong lead over Capriles, mainly thanks to huge state spending on popular social projects, as well as his charisma and strong emotional connection with the country's poor majority.
Venezuelan opinion polls, however, have long been highly divergent and controversial, with accusations of bias filling the airwaves every time a new one is published.
Three surveys that came out this month gave Chavez a lead in voter intentions of between 52 percent and 57 percent, versus 22 percent to 34 percent for Capriles. Then a fourth put them just one point apart: 46 percent for Chavez and 45 percent for his opponent.
Before he left for Havana on Saturday, Chavez hammered the opposition during a televised cabinet meeting. He regularly says his political foes are "ultra-right" U.S. puppets determined to destabilize the country and cause chaos and bloodshed.
"So now they've started to put out some polls saying it's a dead heat. Well, behind that is a violent plan," he said. "This is written: there'll be a great Bolivarian victory this October 7."
Chavez repeatedly refers to this October's election as a re-run of the Battle of Carabobo, the decisive engagement in June 1821 between Spanish colonial forces and troops led by his hero, Simon Bolivar, that led to Venezuela's independence.
Bolivar's soldiers, including several hundred British, Irish and German volunteers, routed the Spanish on the road between Valencia city and Puerto Cabello on the Caribbean coast. More than 3,000 people were captured, wounded or killed.