Jose Serra, presidential candidate for the opposition Brazilian Social Democracy Party, leads voting polls ahead of the nation's 2010 general elections, according to a survey published on Sunday.
Serra, who is also governor of the industrial state of Sao Paolo, won 37 percent of the opinion polls, according to pollster Datafolha, which interviewed 4,100 voters across 171 Brazilian municipalities on Tuesday, Wednesday and Thursday last week.
Dilma Rouseff, candidate for the ruling Workers' Party (PT), was in the second place with 16 percent in favor. Rouseff works as cabinet chief for Brazilian President Luis Inacio da Silva.
Ciro Gomes of the Brazil Socialist Party came out third garnering 15 percent favorable votes.
Serra's 21-point lead, though still substantial, is the narrowest since the presidential race began. In last month's poll, he won 22 points more than his rivals, and in last March he was 35 points ahead.
Rouseff, who is also fighting lymphatic cancer, is best known as the coordinator of the four-year state-run investment strategy -- the Growth Acceleration Plan. She is almost always at the president's side during public events.
The pollster said that a snap vote would take Rouseff and Serraon to a second-round run-off, during which Rouseff would probably pick up the first-round votes that went to Gomes who is a close ally of the president, a former trade union leader.
Ranked fourth with 12 points of the vote was Heloise Helena, candidate for the Freedom and Socialism Party and a senior official belonging to Lula's Workers' Party.
In the fifth place with 3 percent of support was Marina Silva, a newcomer in the survey who currently works as the environment minister. Silva has not declared candidacy for any party, but was invited to stand as the Green Party's presidential candidate last week. She has won international fame for her work in defending the nation's Amazon rainforest.