RIO DEIRO (Reuters) - Support for President Dilma Rousseff continues to slip ahead of October's elections, according to a poll released Tuesday, but she remains comfortably ahead of her two main rivals.
Rousseff, a leftist from the ruling Workers' Party, would receive the vote of 38 percent of those surveyed by pollster IBOPE, compared with 40 percent in May.
Aecio Neves, the senator from the centrist PSDB party who is Rousseff's biggest rival, was backed by 22 percent of those polled, up from 20 percent.
Eduardo Campos, governor of the northeastern state of Pernambuco and the candidate for a rival leftist party, polled 13 percent and was also up two points from 11 percent in May.
Despite what remains a solid lead, Rousseff's approval ratings over the past year have suffered because of a stagnant economy, persistent inflation, protests over public spending on the upcoming World Cup of soccer and a series of scandals at the state run energy company, Petroleo Brasileiro SA, or Petrobras.
The number of Brazilian voters who said they would never vote for Rousseff has risen to 38 percent in June from 33 percent in May. By comparison, the rejection rate for Neves was 18 percent.
The IBOPE poll confirmed other recent surveys of voter opinions that point to the election going to a second round in which Rousseff will prevail, although with a tighter result.
In a run-off against Neves, Rousseff would win 42 percent of the votes against 33 percent for Neves, a gap that narrowed to 9 percentage points from 19 percentage points just a month ago, the poll said.
The IBOPE survey polled 2002 people between June 4 and June 7. The poll has a margin of error of plus or minus two percentage points.
(Reporting by Alexandre Caverni. Editing by Andre Grenon)