Flávio Bolsonaro leads Brazilian President Luiz Inácio Lula da Silva in a hypothetical presidential runoff, according to a survey by Futura Inteligência released on Thursday.
The poll shows Bolsonaro, of the Liberal Party (PL), with 49.4 percent of voting intentions in a potential second-round contest, compared to 43.7 percent for Lula, who represents the Workers' Party (PT).
In that head-to-head scenario, 5.6 percent of surveyed voters indicated they would cast a blank or spoiled ballot, or vote for neither candidate. Those who remained undecided accounted for 1.3 percent.
Flávio Bolsonaro is a federal senator for Rio de Janeiro and the eldest son of former president Jair Bolsonaro. President Lula is serving his third term after returning to office in 2023. Under Brazilian electoral rules, if no presidential candidate secures an absolute majority of valid votes in the first round, the top two finishers contest a runoff.
Runoff Simulations With Caiado and Zema
The research institute also tested four additional second-round simulations against the incumbent president. Taking into account the study's margin of error of 2.2 percentage points, Lula would find himself in a statistical tie with three potential rivals and would trail a fourth.
In a simulated contest between Ronaldo Caiado, of the Social Democratic Party (PSD), and Lula, the former governor of Goiás received 46.5 percent of voting intentions against 42.4 percent for the president. Blank ballots, null votes, or choices for neither candidate stood at 9.7 percent, while 1.3 percent of voters were undecided.
Caiado is an experienced conservative politician and physician who has served as a federal lawmaker and state governor representing Goiás.
A separate simulation involving Romeu Zema, of the Novo party, put the Minas Gerais governor at 43.8 percent against 43.3 percent for Lula. Those intending to cast blank or spoiled ballots, or vote for neither candidate, totalled 11.2 percent, while undecided respondents reached 1.7 percent.
Matchups Against Santos and Cury
In a potential runoff against Renan Santos, of the Missão party, Lula recorded 43.8 percent of voting intentions, while Santos registered 41.7 percent. In that matchup, blank, null, or neither votes accounted for 13.2 percent, and 1.3 percent of participants remained undecided.
The survey showed author Augusto Cury, representing the Avante party, defeating Lula when factoring in the study's margin of error. In that simulation, Cury attracted 46.3 percent of voter support compared to 41 percent for Lula. Blank ballots, null votes, or choices for neither contender stood at 10.9 percent, with 1.8 percent undecided.
Cury is a best-selling writer and psychiatrist known for his books on psychology, while Santos is an activist who rose to prominence through conservative youth mobilization.
Survey Methodology and Campaign Disputes
Futura Inteligência conducted the survey by telephone, questioning 2,000 voters between September 19 and September 23. The study has a margin of error of 2.2 percentage points, plus or minus, with a 95 percent level of confidence.
The polling project was financed entirely with the institute's own funds. It was formally registered with the Superior Electoral Court, Brazil's top electoral tribunal, under registration number BR-05268/2026. The tribunal oversees federal balloting and enforces legal reporting standards for published campaign research.
The findings arrive amid rising political maneuvering between the camps. Lula's coalition has petitioned the Superior Electoral Court over Bolsonaro's radio and television broadcasts, while advisers have urged Bolsonaro to meet with Catholic women voters. Lula has also sought to revive Sarney-style consumer price monitors against his opponent.
