Sen. Flavio Bolsonaro, the eldest son of former Brazilian President Jair Bolsonaro, leads incumbent President Luiz Inácio Lula da Silva by less than one percentage point ahead of Brazil’s October 25 presidential runoff, according to a CNT/MDA poll released Friday.

The survey found that Flavio Bolsonaro would receive 46.8% of the vote, compared with 45.9% for Lula. When blank ballots and undecided voters are excluded, Bolsonaro’s lead grows slightly, with 50.5% of valid votes compared with 49.5% for the incumbent.

MDA conducted the poll between October 13 and 15, surveying 2,014 people. It has a margin of error of 2.2 percentage points, meaning the candidates remain statistically close and the results do not establish a clear advantage for either contender.

The findings mark the first CNT/MDA poll released since Bolsonaro unexpectedly finished ahead of Lula in the first round of voting earlier this month. His performance has put renewed focus on the political strength of Brazil’s conservative movement as voters prepare to choose between the two candidates.

Flavio Bolsonaro is seeking to build on the political base established by his father, Jair Bolsonaro, a former president and leading figure on Brazil’s right. Lula, meanwhile, is seeking another term after returning to the presidency in 2023.

The runoff is shaping up as a major test of support for Brazil’s political direction, with economic policy, public security and the country’s ideological divide likely to remain central issues for voters.

Although the latest poll puts Flavio Bolsonaro narrowly ahead, the close figures and margin of error underscore the contest's uncertainty. The October 25 vote will determine whether Brazil continues under Lula’s left-wing government or elects the son of the country’s former right-wing president.