(CNN) -- Venezuela's vice president says President Hugo Chavez is "fighting for his health" after cancer surgery, and he slammed the opposition for trying to take advantage of the situation and steal power.
Nicolas Maduro gave no other details about Chavez's condition in an interview Friday night on state television.
Chavez, 58, has not been seen in public since arriving in Cuba for his fourth cancer operation more than three weeks ago, which has fueled speculation that his health is worse than the government is letting on.
Thursday, a government spokesman said Chavez was battling a severe lung infection that has caused respiratory failure. Ernesto Villegas said the president was following a strict treatment regimen for "respiratory insufficiency" caused by the infection.
The president's illness has cast doubt on whether he will be able to be inaugurated next week for his fourth term. There is debate over what the constitution requires for a president to take the oath of office in this circumstance.
If Chavez is unable to be sworn in before lawmakers on January 10 as scheduled, the constitution says Chavez can be sworn in before the country's Supreme Court. But the wording of the constitution isn't clear on whether the inauguration before the Supreme Court must happen January 10, whether it must occur inside the country, and who should run Venezuela in the meantime.
Holding up a copy of Chavez's "Little Blue Book," a small copy of the constitution, Maduro said Friday the opposition is trying to manipulate the wording of the constitution to allow them to take power.
He said opposition leader Ramon Guillermo Aveledo sent a letter to Venezuela's ambassadors around the world saying that if Chavez cannot go to the inauguration, power should go to the president of the National Assembly for 30 days.
Maduro said that reading of the constitution is false, and that the swearing-in date is flexible. He urged a national debate to determine what the constitution actually says.
"Let's have this conversation with the people so that the Venezuelans (can determine it) themselves," Maduro said on state-run VTV.
He asked all Venezuelans to read their copy of the constitution and "make their own interpretations about the spirit of our constitution and what it establishes."
Maduro said supporters of the government will protect the constitution "with strength from the streets."
The vice president and another top Chavez ally accused opposition leaders Thursday of organizing a campaign to spread rumors about the Venezuelan president's health.
Standing side by side on the floor of a coffee factory in Caracas, Maduro and National Assembly President Diosdado Cabello sharply criticized the opposition in remarks broadcast on VTV.
"Don't fall victim to the opposition's rumors. ... They have bad intentions every time they talk," Cabello said.
Maduro said opposition claims that officials have been withholding information are baseless, noting that authorities had released dozens of communiques about Chavez's health in the past 22 days.
Another opposition leader denied Friday there are divisions among Venezuelans.
"These pseudo-governors of the government will not change our feelings of solidarity with their hate," Henrique Capriles Radonski, who ran against Chavez in October's presidential election, wrote on Twitter. "The vast majority of Venezuelans are characterized by solidarity."
CNN's Catherine E. Shoichet contributed to this report.