In the poll, Dilma has 45% of intended votes, with Serra at 29% and Marina Silva 8%. The other six candidates did not register 1% altogether. The error margin of the poll is give or take 1.8%.

The poll also registered 5% who would not vote (blank votes) and 12% undecided.

Vox Populi polled 3,000 voters in 219 municipalities between August 7 and 10.

Under Brazilian election rules, if the election took place today Dilma would be elected on October 3, with no need for a runoff on October 31. That is because, although she would have less than a majority, she would nevertheless have more votes than all the other candidates together.

In a previous poll by Ibope, the candidate handpicked by Lula Brazilian had already widened her lead to 11 percentage points over opposition candidate.
 
"A first-round win for Dilma is looking increasingly likely," said Rafael Cortez, a political scientist at Tendências Consultoria Integrada in São Paulo.

Candidates now are being allotted free TV and radio advertising slots. This will increase support for Rousseff among voters who remain undecided, said Cortez.

"These are mainly voters with low income levels, who have difficulty getting political information," Cortez said. Rousseff "is going to gain ground precisely in these sectors."

Rousseff, former cabinet chief to President Lula, rose to 43% from 39% in the previous poll taken August 2-5, Globo said. Support for former Sao Paulo Governor Serra, the Social Democracy Party candidate, fell to 32% from 34%, according to Globo.

Green Party candidate Marina Silva had 8%; minor candidates had less than 1% combined. The nationwide poll of 2,506 people was taken between August 12 and 16 and has a margin of error of two percentage points, according to Globo.

In related news the leading opposition candidate for vice-president accused the ruling Workers' Party of having relations with the Colombian FARC guerrillas, sparking controversy during a tranquil debate among vice-presidential hopefuls.

José Índio da Costa, running with José Serra challenged the PT and its presidential candidate Dilma Rousseff to explain the relationship.

"The issue is that the PT has relations with the FARC, which are linked to drug-trafficking" said Da Costa in a debate organized by the O Estado de Sao Paulo newspaper. "Dilma has to give explanations.

"If the FARC call me to a meeting, I take the federal police and I arrest them," he said. "The FARC are not a social movement".

His comment sparked one of the few feisty replies from Deputy Michel Temer, vice-presidential candidate for the ruling coalition.

"To associate Dilma with drug-trafficking is very serious. I don't think that is the case," said Temer, president of the Lower House. "There is no relationship between Brazilian government and the FARC, or between Dilma and the drug-trafficking."