The Venezuelan Catholic Church has said that delaying President Hugo Chavez's inauguration would be a "morally unacceptable" violation of the constitution.
The head of the Venezuelan Conference of Bishops, Diego Padron, said Mr Chavez must attend his inauguration when his term ends on 10 January.
Attorney-General Cilia Flores says the swearing-in can take place later.
The Venezuelan leader is in Cuba where he underwent cancer surgery last month.
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