Polling conducted by CNT/MDA places Flávio Bolsonaro, the Rio de Janeiro senator, at 50.5% of valid votes against 49.5% for President Luiz Inácio Lula da Silva in a projected 2026 Brazilian presidential runoff. Published on Friday, 16 October, the poll's findings placed the two sides within a margin narrow enough to constitute a statistical dead heat.

The polling work was carried out by research firm MDA on behalf of the Confederação Nacional do Transporte, a Brazilian industry body representing transport operators. The poll drew on responses from 2,002 voters aged 16 and above and was conducted between 13 and 15 October, carrying a sampling margin of 2.2 percentage points, according to one broadcaster's coverage.

Polling numbers released by a news outlet placed Flávio Bolsonaro at 46.8% of total voting intentions, with Lula trailing at 45.9%, while blank or null responses accounted for 4.9% and those yet to decide made up the remaining 2.4%. Among valid ballots — once spoiled and blank papers were removed from the count — one camp secured 50.5% of the vote, leaving the other with 49.5%.

Data from the CNT/MDA poll released on 3 October placed Lula ahead in a runoff matchup by a margin of 47.3% to 43.1%, according to a news channel's coverage of that earlier survey. Across all voting-intention categories, Flávio's share climbed by 3.7 percentage points while Lula's figure dropped 1.4.

Surveys conducted by additional polling organisations point to a similarly narrow gap between the candidates. Two polls conducted on consecutive days placed Flávio ahead in the race: Datafolha, surveying on 15 October, put him at 51% against 49% among valid votes, while Quaest's 14 October figures showed him leading 46% to 44% across total votes cast.

When two candidates' numbers fall within the survey's margin of error, their standings are statistically indistinguishable. A margin of error of 2.2 points on every figure leaves the poll unable to establish a definitive lead for either candidate. Because polling methods and interview windows vary from one survey to the next, any individual result captures public opinion only at the specific point when those interviews took place.

Betting contracts on Polymarket — a web-based prediction exchange — placed Flávio Bolsonaro's probability of taking the 25 October runoff at 76.5%, with Lula's corresponding figure standing at 22.5%, as of 2:17 p.m. ET on 16 October. Trading volume across the platform reached a combined value of approximately US$184.7 million. Runoff contracts are also available on Kalshi, a trading platform operating under CFTC oversight in the United States.

How far eleventh-hour developments — including the Senate's vote to end the six-days-on, one-day-off working arrangement — actually moved voters is an open question, given that data collection for the poll closed on 15 October. How much opinion has shifted will become clear only when the next round of surveys is published.

What the undecided voters — recorded at 2.4% of respondents — will do on 25 October, or whether they will cast a ballot at all, remains an open question. Polling data reflects where opinion stands at the time of collection, not where ballots will land when counting is done.

Polling firm MDA conducted the research on behalf of the CNT, a Brazilian transport industry body known formally as the National Transport Confederation. Under the reference BR-00652/2026, the filing holds formal standing before the electoral court.