Chavez rejects poll debate, irking rival

His actual condition and capacity to carry on with his typically torrid pace of campaigning are still shrouded in mystery. News reports that he has only a few months to live continue to surface, as they have periodically since he announced his cancer last June.

One source close to Chavez's medical team told Reuters his condition was "delicate" and he had started to experience strong pain in one leg last month due to the illness' progression.

Reporters, including one prominent opposition journalist, have said Chavez is taking powerful opiates to ease the pain of what they said was cancer that had spread to his bones.

The cancer has given an extraordinary backdrop to the election and is eclipsing all other major factors in the campaign - including an unprecedented push by the opposition to rally behind a single candidate.