CARACAS, Venezuela — Venezuelan lawmakers voted on Tuesday to postpone the inauguration of ailing President Hugo Chavez for his new term, prompting complaints from opponents who called it a violation of the constitution.

Chavez's congressional allies, who hold a majority of seats in the National Assembly, agreed with a government proposal for Chavez to be sworn in at a later date before the Supreme Court. While pro-Chavez lawmakers approved the plan with a show of hands, opponents condemned the action as illegal.

Vice President Nicolas Maduro broke the news that Chavez would not be able to attend Thursday's scheduled inauguration in a letter to National Assembly President Diosdado Cabello, confirming suspicions that Chavez's battle with cancer and a related respiratory infection would keep him in a Cuban hospital past the key date.

Maduro said that on the recommendation of Chavez's medical team, his recovery process "should be extended beyond Jan. 10."

The vice president said Chavez was invoking a provision in the constitution allowing him to be sworn in before the Supreme Court at a "later date."

The opposition disputed that argument and appealed to the Organization of American States, but did not appear to have other routes to put the brakes on the government's plan.

Tensions between the government and opposition have been building for days in the dispute over whether the ailing president's swearing-in can legally be postponed. The president underwent his fourth cancer-related surgery in Cuba last month and hasn't spoken publicly in a month.

Opposition leader Henrique Capriles said earlier Tuesday that Chavez's current term constitutionally ends Thursday and that the Supreme Court should rule in the matter.

Other opposition leaders have argued that the inauguration cannot legally be put off and that the National Assembly president should take over as interim president if Chavez hasn't returned from Cuba on inauguration day.

"The Supreme Court has to take a position on what the text of the constitution says," said Capriles, who lost to Chavez in presidential elections three months ago. "There is no monarchy here, and we aren't in Cuba."