Diosdado Cabello, a Hugo Chavez ally who was re-elected as leader of Venezuela's National Assembly on Saturday, could be a stand-in for the ailing leader.
Cabello, a longtime Chavista and former army comrade of Chavez, was expected to be re-elected in the Assembly, which is heavily dominated by the governing United Socialist Party of Venezuela, BBC News reported.
"As a fellow countryman of the beautiful Venezuelan people, I swear that I shall fully comply with my duties and faithfully defend the homeland and this beautiful revolution led by Hugo Chavez," Cabello said during his swearing-in ceremony, after which a prayer for Chavez was offered by a chaplain of the Catholic Church, El Universal reported.
President Chavez's health is a growing concern in the country and the region: he has been in Cuba since early December, where he underwent his fourth pelvic surgery for cancer, the Los Angeles Times reported.
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While the opposition has called for new presidential elections, Vice President Nicolas Maduro has said that Chavez will maintain his role as the country's leader even if he is too weak to attend his inauguration on January 10, leaving Maduro as the de-facto head of state in the meantime.
"The president will continue being president beyond January 10, nobody should have any doubt about that," Cabello said, according to BBC News. "We will never defraud the people."
Cabello would become the leader of Venezuela if Chavez is declares too sick to perform his presidential duties or is not sworn in, Bloomberg Businessweek reported.
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