In December, Chávez reappointed Cabello as vice president of the ruling Unified Socialist Party of Venezuela, or PSUV. And last month, Cabello was named president of the National Assembly.

“He has become more relevant and much more visible,” Cabrera said. “He’s on the crest of the wave.”

Even so, surveys that Consultores 21 conducted last year suggested the PSUV could not win the presidency without Chávez on the ticket.

Even if he does make a quick recovery, the way Chávez has handled the health issue has become contentious, said Elsy Manzanares, the host of Uno Levanta, a Venezuelan radio show that covers politics and news.

For weeks, the president had been telling supporters that he was out of the woods and ready to put up a vigorous fight against his rival — Miranda Gov. Henrique Capriles Radonski.

As rumors churned last week that his health was failing, Chávez and his ministers came out fighting. Early Tuesday, just hours before Chávez said he would undergo more surgery, the minister of communications and Cabello both blasted the media for questioning his health.

The fact that even his own ministers appear to be in the dark is alarming, Manzanares said.

“This raises some serious credibility issues among some of his more rational supporters,” she said. But his die-hard followers are likely to forgive him. “They treat Chavismo like a religion. No matter what he does, they say ‘Amen’ ”

While Chávez has admitted that he had a baseball-sized tumor removed from his abdomen in June, he never said what type of cancer it was or what organs were being affected.

Doctors have speculated that prostate, colon or bladder cancers are likely culprits. But rarer forms of soft-tissue cancers are also possible.

On Tuesday, the coalition of opposition parties, which is backing Capriles, called on the administration to be more forthcoming.

“The speculation and stories that circulate are directly related to the secrecy and lack of precise clear and medically trustworthy information,” the organization wrote in a communiqué. “Telling the truth is a democratic duty to the Venezuelan people.”

Cabello announced Wednesday that a prayer vigil for the president will be held Thursday and said Chávez would be asking congress for permission to travel — a request that’s mandatory for absences of five days or more.

But as of late Wednesday, Chávez had not designated an interim president and hadn’t said when he will go to Cuba.