Voters in Brazil to choose between Lula and Bolsonaro's son

Brazil votes on Sunday in a high-stakes presidential runoff that will decide whether incumbent Luiz Inácio Lula da Silva wins a fourth term in office or hands power to Flávio Bolsonaro, a senator who has channelled his imprisoned father's movement into a formidable electoral force. Neither candidate secured the absolute majority required to avoid a second round when Brazilians first went to the polls on October 4.

Flávio Bolsonaro, 45, defied pre-election surveys in the first round by finishing ahead of Lula with 47 percent of valid votes to the president's 44.9 percent, a gap of roughly three million ballots. Political analyst Rafael Favetti described the result as a warning to the incumbent. "The protest vote foreshadows what is to come in the run-off," Favetti said after the count.

Polling in the final days before Sunday's vote has shown the contest narrowing. A Nexus survey put Flávio Bolsonaro at 46.5 percent against Lula's 45.9 percent, while an AtlasIntel poll conducted for Bloomberg gave Bolsonaro a slightly wider edge of 49.8 percent to 47.6 percent. A Quaest survey published on October 21 found the candidates separated by just one percentage point.

Lula, who turns 81 next month, is seeking what he has described as a fourth and likely final term. He governed Brazil from 2003 to 2010, spent 580 days in prison on corruption convictions later annulled by the Supreme Court in 2021, and returned to the presidency in 2023 after narrowly defeating Jair Bolsonaro in that year's election. His campaign has centred on social programmes, poverty reduction, Amazon conservation, and the defence of democratic institutions.

Flávio Bolsonaro's father, Jair, is barred from standing for office and is serving a 27-year sentence handed down after a court found him guilty of plotting a coup to overturn his 2022 election defeat. The elder Bolsonaro is currently under humanitarian house arrest on health grounds. Flávio has made his father's release a campaign pledge, framing it as part of what he calls a constitutional "redemocratisation" of Brazil.

Beyond the father's fate, the right-wing senator has campaigned on a militarised approach to crime, tighter debt controls, inflation reduction, and closer ties with the United States. The first round also saw strong legislative gains for the right, with Bolsonaro's Liberal Party on course to become the largest bloc in the Chamber of Deputies. Former first lady Michelle Bolsonaro and Carlos Bolsonaro, another of Jair's sons, both won Senate seats.

The vote arrives amid broader concerns about foreign interference in Brazil's information environment. Allegations that Meta's social media platforms have amplified disinformation have become a prominent issue in the final stretch of the campaign. The electoral court has been monitoring online content, adding a layer of institutional tension to an already polarised contest.

Lula's campaign has sought to draw a sharp contrast on democratic values, arguing that a Bolsonaro return to power — even in a new generation — poses a risk to the institutions that survived the upheaval of January 2023, when Jair Bolsonaro's supporters stormed government buildings in Brasília following his election loss. Flávio's team rejects comparisons with that episode and insists his candidacy represents a break from his father's more confrontational style.

The outcome carries implications well beyond Brazil's borders. Latin America's largest nation has watched neighbouring countries — including Argentina and, before it, several smaller states — swing sharply to the right in recent electoral cycles. A Flávio Bolsonaro victory would mark a decisive tilt in that direction for a country of 215 million people and the world's ninth-largest economy.

Voting centres across Brazil open early on Sunday morning, with official results expected later in the evening. Both campaigns have urged their supporters to turn out in large numbers, reflecting how razor-thin the margins have remained throughout the final weeks of a race that will shape Brazilian politics for the next four years.