Brazil Election 2026: Lula Leads First Round, Runoff a Dead Heat in Final AtlasIntel Poll

Brazil · Election 2026

Brazil’s presidential race closed September with a split picture: President Lula has widened his first-round lead over senator Flávio Bolsonaro in the last AtlasIntel poll before Sunday’s vote, yet a head-to-head runoff remains a statistical dead heat.

Recent runoff polling between Lula and Flávio Bolsonaro has tightened into a statistical tie. (Chart: The Rio Times)

What the Poll Shows

AtlasIntel released the survey on Tuesday 29 September, five days before the first round. In the main stimulated scenario, counted on valid votes — which exclude blank, null and undecided ballots — President Luiz Inácio Lula da Silva (PT) leads with 46.2%, followed by senator Flávio Bolsonaro (PL) on 43.1%. Renan Santos (Missão) holds third place with 5.3%, ahead of writer Augusto Cury (Avante) on 2.1%, Ronaldo Caiado (PSD) on 1.8% and Romeu Zema (Novo) on 0.9%; the remaining candidates together account for 0.5%.

On the broader measure that counts all voting intentions rather than valid votes only, Lula scores 45.3% against Flávio Bolsonaro’s 42.2%, according to figures reported by the legal news portal JOTA. JOTA notes that the distance between the two front-runners grew again after two consecutive waves in which the gap had sat at the narrowest level of AtlasIntel’s 2026 series.

A Runoff Too Close to Call

The headline finding for a potential second round is a dead heat: Lula and Flávio Bolsonaro are tied at 50% each on valid votes. Counting all responses, Poder360 reports Flávio Bolsonaro at 47.7% and Lula at 47.6%, with 4.8% saying they would vote blank, null or did not know — a gap of a tenth of a point, far inside the margin of error.

AtlasIntel simulated four further runoff scenarios, all featuring Lula. The president leads Romeu Zema by 53.5% to 46.5% and Ronaldo Caiado by 51.4% to 48.6% — the latter a competitive but outside-the-margin gap on valid votes. Against Augusto Cury the advantage stretches to 56.1% to 43.9%, and against Renan Santos to 61.6% to 38.4%. No scenario tested shows any challenger defeating Lula outright, but the Flávio Bolsonaro pairing is the only one in which the challenger draws level.

How the Race Has Moved

The scale of the 2026 tightening is visible inside AtlasIntel’s own series. In late July the institute measured Lula at 44.9% of first-round intentions against 35.8% for Flávio Bolsonaro — a nine-point advantage. Through August and early September the challenger closed steadily, and the past fortnight produced the closest readings of the campaign: a week ago the institute’s runoff simulation showed Flávio Bolsonaro marginally ahead, 47.2% to 46.8%, while the first round stood at 45.8% to 43.4%.

The new wave therefore marks a double movement: Lula’s first-round cushion has re-widened from its series low, while the runoff — the scenario that decides the presidency if no one wins outright on Sunday — remains locked in a tie. Poll aggregator averages that blend AtlasIntel with Datafolha, Quaest and BTG/Nexus have consistently shown a somewhat wider Lula advantage, which points to genuine divergence between institutes rather than a settled consensus.

Five Days Out: What It Means

Brazil votes on Sunday 4 October. A candidate needs more than half of valid votes to win in the first round; failing that, the top two meet in a runoff on Sunday 25 October. On these numbers a first-round outright win is out of reach for both front-runners, making 25 October the likeliest decision date — and turning the final week of campaigning, including the last televised debate on Globo on Thursday 1 October, into a fight over the narrow band of undecided voters.

One striking divergence persists between pollsters and prediction markets: as The Rio Times reported this week, betting markets continue to price Flávio Bolsonaro as the favourite even as surveys show a tied runoff and a first-round Lula lead. Both cannot be right for long; the resolution arrives on Sunday night, when Brazil’s electronic ballot boxes deliver results within hours of polls closing.

What We Could Not Confirm

A poll is a snapshot of fieldwork conducted 23–28 September, not a forecast of Sunday’s result; late campaign events can move numbers after fieldwork closes. Institutes diverge meaningfully in 2026: Datafolha, Quaest and BTG/Nexus have at times shown wider Lula leads than AtlasIntel, and the institute’s own series has swung from a nine-point first-round gap in July to a near-tie and back within two months. Poder360’s report referenced a second runoff scenario whose full figures we could not independently verify. How the 4.8% of blank, null and undecided respondents will behave in a runoff is not measurable from this survey.

Frequently Asked Questions

What does the final AtlasIntel poll show for Brazil’s 2026 election?

Released on 29 September, the poll puts Lula on 46.2% of valid first-round votes against 43.1% for Flávio Bolsonaro, with Renan Santos third on 5.3%. A runoff between the two leaders is tied at 50% each on valid votes.

When does Brazil vote in the 2026 presidential election?

The first round is on Sunday 4 October 2026. If no candidate wins a majority of valid votes, the two front-runners contest a runoff on Sunday 25 October 2026.

How reliable is the AtlasIntel survey?

The institute interviewed 5,005 voters between 23 and 28 September 2026, with a margin of error of one percentage point and 95% confidence, under electoral-court registration BR-04391/2026. Other institutes show somewhat different gaps, so the poll is best read alongside aggregator averages.