"In the past hours, we've been accompanying President Hugo Chavez and taking him the courage and strength of the Venezuelan people," Maduro said on television. Appearing next to Cabello visiting a government-run coffee plant in Caracas, he said they had been with Chavez together with the president's brother, his son-in-law Jorge Arreaza, Oil Minister Rafael Ramirez and Attorney General Cilia Flores.
Chavez's health crisis has raised contentious questions ahead of the swearing-in set for Jan. 10, including whether the inauguration could legally be postponed, whether Supreme Court justices might travel to Havana to administer the oath of office, and, most of all, what will happen if Chavez can't begin his new term.
The main fault lines run between Chavez's backers and opponents.
But while the president's allies so far appear united, analysts have speculated that differences might emerge between factions led by Maduro, Chavez's chosen successor, and Cabello, who is thought to wield power within the military and who would be in line to temporarily assume the presidency until a new election can be held.
Standing together on Thursday, Maduro and Cabello said they are more united than ever.
"We've sworn before commander Hugo Chavez, and we've ratified the oath today before commander Chavez, that we're going to be united, together with our people, with the greatest loyalty," Maduro said.
He and Cabello dismissed rumors of divisions waiting to erupt, calling such talk lies cooked up by their adversaries.
"They're going to spend 2,000 years waiting for that to happen," Cabello said, urging Venezuelans: "Don't fall for the opposition's rumors."
"We aren't going to betray the nation," Cabello added.
The former military officer has been making similar assurances on Twitter and suggesting that the socialist party has its plans for the coming days all thought out.
"We Chavistas are very clear on what we will do," Cabello said in one message.
But the plans of Chavez's allies remain a mystery.
The Venezuelan Constitution says the presidential oath should be taken Jan. 10 before the National Assembly, and officials have raised the possibility that Chavez might not be well enough to do that, without saying what will happen if he can't.
Information Minister Ernesto Villegas provided the latest update on Chavez's condition Thursday night.
"Chavez has faced complications as a result of a severe respiratory infection. This infection has led to respiratory deficiency that requires Commander Chavez to remain in strict compliance with his medical treatment," Villegas said, reading from a statement.
The government expressed confidence in Chavez's medical team and condemned what it called "a campaign of psychological warfare" in the international media regarding the president's condition.
Chavez said before his fourth cancer-related operation that if his illness prevented him from remaining president, Maduro should finish his current term and be his party's candidate to replace him in a new election.
The constitution says that if a president or president-elect dies or is declared unable to continue in office, presidential powers should be held temporarily by the president of the National Assembly, who is now Cabello. It says a new presidential vote should be held within 30 days.
Opposition leaders have argued that Chavez, who was re-elected to a six-year term in October, seems no longer fit to continue as president and have demanded that a new election be held within 30 days if he isn't in Caracas on inauguration day.
But some of Chavez's close confidants dismiss the view that the inauguration date is a hard deadline, saying Chavez could be given more time to recover from his surgery if necessary.
Cabello noted last month that the constitution says if a president is unable to be sworn in by the legislature, he may be sworn in by Supreme Court justices, who were appointed by the mostly pro-Chavez legislature.
"When? It doesn't say. Where? It doesn't say where," Cabello recently told a crowd of government supporters. His indication that the constitution does not specify where a president-elect should be sworn in by the Supreme Court has led to speculation that justices could travel to Cuba for the ceremony.
Opposition leaders chafe at the suggestion that Chavez could take office from a foreign country, saying the president made it clear before he left for the operation that his health was deteriorating by designating Maduro as his successor.
Aristobulo Isturiz, a state governor and leader of Chavez's United Socialist Party of Venezuela, said Thursday that if Chavez's swearing-in isn't held Jan. 10, it will be up to the Supreme Court to determine the place and date of the ceremony.
"The president has a right to recover," Isturiz said in remarks published by the state-run Venezuelan News Agency.
More than three weeks after Chavez's cancer surgery, government officials have been providing vague and shifting updates on his condition. Maduro announced over the weekend that Chavez had suffered complications due to a respiratory infection and was in "delicate" condition.
The vice president initially had said he would return from Cuba to Venezuela on Wednesday, but stayed another day while visiting Chavez along with Cabello and others.
Maduro said Chavez's respiratory problems "have seriously affected him."
Still, Maduro expressed hope: "In our hearts, we feel it, sooner rather than later we're going to see commander Hugo Chavez here in his homeland, here with us."
Caracas Mayor Antonio Ledezma, an opposition politician, proposed earlier Thursday that a commission travel to Cuba to determine the state of Chavez's health. He said the delegation should be made up of doctors, lawmakers and other officials such as state governors, including opposition leader Henrique Capriles.
"I'm not asking for permission to go to Cuba. I think it's our right to go there and see what's going on," Ledezma said in comments reported by the television channel Globovision. "Enough mysteries. Venezuela isn't a colony of Cuba."
Some of the brewing disagreements could begin to be aired Saturday, when the National Assembly, which is controlled by a pro-Chavez majority, convenes to select legislative leaders. That session will be held just five days before the scheduled inauguration day.
Law professor Vicente Gonzalez de la Vega agrees with Cabello's view that the constitution is ambiguous regarding the time and place of a swearing-in ceremony before the Supreme Court.
Supreme Court President Luisa Estella Morales said following Cabello's proposal last month that justices could rule on whether it's constitutional to postpone the date of the swearing-in ceremony. The issue has not yet been brought before the court, but Morales said Dec. 20 that the court could take up such issues if asked and would have the final word.
Before Chavez's inauguration date could be postponed, Gonzalez said, lawmakers would have to approve a 90-day extension of Chavez's "temporary absence" granted for his trip to Cuba for surgery. The president of the National Assembly would then be sworn in as an interim president for 90 days, said Gonzalez, a professor at the Central University of Venezuela.
In order for that to occur, though, Gonzalez said the Supreme Court would need to appoint a panel of doctors to examine Chavez to determine whether his health could improve and whether he might be capable of continuing his duties as president.
Opposition leader Ramon Guillermo Aveledo on Wednesday reiterated demands for the government to provide a full medical report.
He said sending a medical team to Cuba to assess Chavez's condition would be an option, if necessary. In the meantime, he said, "There are two keys here to facing this and any situation, which are the truth and the constitution."