Former Brazilian President Luiz Inacio Lula da Silva has widened his lead over incumbent Jair Bolsonaro to 10 points ahead of next month’s presidential election, a Genial/Quaest poll released on Wednesday showed.

The bitter rivals are locked in a battle to lead Latin America’s largest economy in a race defined by a deeply polarized Brazil.

The new survey put support for Lula at 44% in the first-round vote on Oct. 2 against 34% for Bolsonaro. A week earlier the leftist Lula was favored by 42% of those surveyed, while the far-right Bolsonaro had 34% support.

In an expected Oct. 30 run-off, Lula’s lead also rose to a 10-point advantage, 50% to 40%, up by 2 percentage points from the previous survey.

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The Genial/Quaest poll found that negative views of Bolsonaro’s government edged up slightly to 39% from 38% last week, while the percentage of those who see the government in a positive light dipped one percentage point to 31%.

Pollster Quaest interviewed 2,000 voters in person between September 17-20.

Its poll has a margin of error of 2 percentage points.