SAO PAULO (Reuters) - Almost two thirds of Brazilians favor the impeachment of President Dilma Rousseff over a corruption scandal at state-run oil company Petrobras, but roughly as many doubt it would drive her from office, according to a poll released on Saturday.
The survey by polling firm Datafolha showed 63 percent of respondents support impeachment in light of the widening police investigation into a huge kickback scheme at Petroleo Brasileiro SA, as the oil giant is formally known.
Still, 64 percent said they did not expect the scandal would be enough to cut short Rousseff's second term, which began in January.
Opposition parties have played down the prospects for impeachment, although they have lent support to protests against Rousseff, including a demonstration scheduled for Sunday.
Rousseff herself is not under investigation in the still-expanding Petrobras probe. She says she knew nothing about the bribery and price-fixing racket that allegedly cost the company billions of dollars while she was chairwoman from 2003 to 2010.
Brazilians remain skeptical of Rousseff's account, according to the Datafolha poll. Of those surveyed, 57 percent said she knew about the graft and allowed it to happen. An additional 26 percent said she knew but could do nothing to stop it.
As the police investigation has gathered steam, implicating senior Petrobras executives, major engineering firms and elected officials, Brazilians have also expressed increasing concern about how corruption is holding their country back.
In the Datafolha poll, 22 percent of respondents said corruption was the biggest problem confronting Brazil, just behind the 23 percent who named the country's health care system. In a July survey, 14 percent said corruption, well behind the 38 percent who said health care.
The latest survey by Datafolha, one of the most respected pollsters in Brazil, confirmed the findings of polling firm MDA, which found last month that 60 percent of respondents favored Rousseff's impeachment.
Testing a theoretical match-up for Brazil's next presidential election, Datafolha found 33 percent of respondents would vote for Aecio Neves, the opposition senator who lost narrowly to Rousseff in October.
Rousseff's predecessor and political mentor, Luiz Inacio Lula da Silva, was close behind at 29 percent, within the poll's margin of error.
(Reporting by Brad Haynes; Editing by James Dalgleish)