Gonzalez said that lawmakers can request a medical report "to see whether he's getting better, whether he can come or not." And if not, he said, a transition process should then begin, including the calling of a new election.
If a president-elect dies or is declared incapacitated before the swearing-in, the constitution says the National Assembly president would temporarily take charge of the government and a new presidential vote would have to be held within 30 days. Chavez has said that if such a vote is held, his supporters should elect Maduro to take his place.
Former Supreme Court magistrate Roman Duque Corredor has ruled out the possibility of authorities going to Cuba for a swearing-in, saying a president cannot take the oath of office outside Venezuela.
Diego Moya-Ocampos, an analyst with the consulting firm IHS Global Insight in London, said that given the control that Chavez's movement has over all state institutions, including the Supreme Court, "any arrangement that could suit the ruling PSUV party political strategies is possible.
"This could include postponing the date of the inauguration for the new term, if needed, or even taking advantage of any legal technicality that could see Chavez formally inaugurating his mandate from Cuba," Moya-Ocampos said. "This will all, of course, depend on Chavez's state of health and what is more strategically convenient to those making the decisions."
The Venezuelan leader underwent his latest operation after tests found his cancer had come back despite previous surgeries, chemotherapy and radiation treatments.
He had said in July that tests showed he was cancer-free, and he was re-elected in October. But Chavez said later he had been suffering swelling and pain that he thought was due both to his exertion during the campaign and to his prior radiation treatments.
Independent medical experts consulted by The Associated Press said that given the government's account of the surgery and complications, they think it is unlikely Chavez would be able to stand up and take the oath of office as scheduled. They also said the vague information available makes it difficult to know the likely course of Chavez's recovery.
Dr. Gustavo Medrano, a lung specialist at the Centro Medico hospital in Caracas, said knowing whether Chavez is on a respirator and in an intensive care unit, and whether he is being given high doses of morphine for pain, would be important to judging where his recovery stands.
Based on the information provided about Chavez's condition, Medrano said that on his inauguration date "he shouldn't be on his feet."
Throughout his treatments, Chavez has kept secret several details about his illness, including the precise location of the tumors and the type of cancer.
Dr. Carlos Castro, scientific director of the Colombian League Against Cancer in Bogota, said much will depend on how Chavez's complications evolve, including the respiratory infection and other infections or bleeding that can develop after such surgery.
"Personally I don't think he can be sworn in on that scheduled date. I don't think Chavez is going to be in shape to," Castro told the AP in a telephone interview.
He said that recovering enough to function as president will probably take at least one or two months if all goes well. He noted that Chavez had mentioned being in serious pain before the operation.
"He still isn't out of danger, and he is still in what I'd call a critical phase in which anything can happen," Castro said.
Associated Press writers Fabiola Sanchez and Ian James contributed to this report.
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