Venezuela has officially postponed the swearing-in ceremony of Hugo Chavez, who has been battling to recover from an infection sustained during cancer surgery at a Cuban hospital.

The Venezuelan National Assembly has voted in favour of the postponement request, made by Chavez, and has promised the socialist leader as much time as he needs to fully recover.

Chavez, 58, is fighting severe lung infection after undergoing his fourth course of cancer surgery on 11 December, and has not been seen in public since then. He had been due to assume office on 10 January.

Vice President Nicolas Maduro read in a letter: "The president wants us to inform that, based on his medical team's recommendations, the post-operative recovery should extend past 10 January. As a result, he will not be able to be present at the National Assembly on that date".

The letter added that the socialist leader will take his oath in front of the Supreme Court at a later date rather than being sworn in by the legislature. A specific date has not been mentioned.

The announcement comes after weeks of speculation on whether or not Chavez will be able to assume office.

The latest decision by the Venezuelan legislators has angered opposition groups who have been championing for a re-election in case of Chavez's absence at the swearing-in ceremony.

Urging the Supreme Court to take a decision on the issue, the opposition has also demanded that the speaker of the National Assembly, Diosdado Cabello, should take over as the interim president.

Chavez's supporters have been urged to take to the streets on 10 January in a show of support for their ailing leader, who has ruled the oil-rich Latin American nation since 1999.

"All of Venezuela will come here in front of the Miraflores presidential palace, the people supporting our president, the people supporting Chavez, in an overwhelming manner, the people in the street," said Cabello.

Despite Chavez's absence, several leaders from other Latin American countries are also likely to visit Caracas on 10 January in a show of solidarity, including Uruguay's Jose Mujica and Bolivia's Evo Morales.

Argentine President Cristina Fernandez de Kirchner is likely to visit Chavez in hospital in Havana.