CARACAS, Venezuela — Venezuelan Vice President Nicolas Maduro would comfortably win a presidential election should his boss Hugo Chavez's cancer force him out of power, according to an opinion poll.

The first survey on such a scenario, by local pollster Hinterlaces, gave Maduro a potential 50 percent of votes, compared to 36 percent for opposition leader Henrique Capriles.

Chavez returned to Venezuela on Monday after a long stay in Cuba to continue treatment at home for the disease that is jeopardizing his 14-year socialist rule of the South American OPEC nation.

He has named 50-year-old former bus driver and union activist Maduro as his preferred successor. But Capriles, 40, a center-left state governor who lost to Chavez in a presidential vote last year, would likely run again.

Chavez still has not said a word in public since his Dec. 11 operation in Cuba, and Venezuelans were debating on Tuesday the various possible scenarios after his homecoming - from full recovery, to resignation, or even death from the cancer.

Should Chavez be forced out, Venezuela's constitution stipulates an election must be held within 30 days.

Capriles, who crossed swords with Hinterlaces at various points during the presidential election, again mocked its director, Oscar Schemel, as being biased against him.

"That man is not a pollster, he's on the government's payroll," Capriles told local TV.

"He said in December I would lose the Miranda governorship," he added, referring to his defeat of government heavyweight Elias Jaua, now foreign minister, in that local race.

Opinion surveys are notoriously controversial and divergent in Venezuela, with both sides routinely accusing pollsters of being in the pocket of the other.

Hinterlaces surveyed 1,230 people between Jan. 30-Feb. 9.