BRAZIL · PROFILE
Runoff · Sunday, 25 October
Flávio Bolsonaro vs Lula: what happens next
First-round results, how the runoff works, the key dates and who backs whom, in one guide.
Key Facts
- —The country Brazil, Latin America’s largest economy, holds a presidential runoff on 25 October between President Lula and conservative senator Flávio Bolsonaro.
- —Who he is Kássio Nunes Marques is a Supreme Court justice appointed by Jair Bolsonaro in 2020 and has led the electoral court since 12 May 2026.
- —What happened On Monday, 12 October, two Workers’ Party deputies asked the Supreme Court to investigate him over the Banco Master case.
- —The Meta clash On Sunday, 11 October, he ordered a pro-Lula WhatsApp channel suspended over Meta’s compliance plan; a fellow judge reversed the order the same day.
- —Prediction markets Polymarket gives Flávio Bolsonaro an 87.5% chance of winning the 25 October runoff (13 October, 4:56 a.m. ET). Polymarket puts Flávio Bolsonaro’s chance of winning at 88% and Kalshi at 87% (Lula: 13% and 13%), as of 13 October, 5:20 am ET; prices are bets, not polls.
- —Still open It is not yet known whether the Supreme Court or the prosecutor-general will act on the deputies’ request.
Kássio Nunes Marques, the Supreme Court justice who runs Brazil’s electoral court, faces a request for a criminal investigation before the presidential runoff. Two deputies from President Luiz Inácio Lula da Silva’s Workers’ Party (PT) filed it on Monday, 12 October, Correio Braziliense and Poder360 reported.
It comes a day after his order against a pro-Lula channel on WhatsApp, owned by the US company Meta, was overturned within hours. For American readers, he is the referee of the 25 October vote that decides who governs Latin America’s largest economy.
Who Is Kássio Nunes Marques
Nunes Marques was born in Teresina, the capital of Piauí state in Brazil’s northeast. He earned his law degree at the Federal University of Piauí in 1994, according to Migalhas and the legal news site ConJur.
He practised as a lawyer and sat on the council of the Piauí bar association. He then served as a judge on Piauí’s regional electoral court, in a seat reserved for jurists.
In 2011 he joined the Federal Regional Court of the 1st Region, a federal appeals court based in Brasília, in a seat reserved for lawyers. He was its vice-president from 2018 to 2020.
He also holds a master’s degree in law from the Universidade Autónoma de Lisboa in Portugal, ConJur reported at his swearing-in.
Bolsonaro’s First Pick for the Supreme Court
Jair Bolsonaro, then president, nominated him in 2020 to replace Justice Celso de Mello, who had retired. The Senate’s justice committee approved him by 22 votes to 5 on 21 October 2020, after a hearing of about ten hours.
The full Senate confirmed him by 57 votes to 10, and he took his seat on the 11-member Supreme Court on 5 November 2020. André Mendonça, Bolsonaro’s second pick, joined in December 2021.
Three Supreme Court justices also sit on the Superior Electoral Court (TSE), which organises and polices national elections. Nunes Marques joined it as a substitute in August 2021 and as a full member in May 2023, Migalhas reported.
He took office as TSE president on 12 May 2026, succeeding Justice Cármen Lúcia, with Mendonça as his deputy. The term runs for two years, Estadão Conteúdo reported in copy carried by Diario de Pernambuco.
The Meta Ruling on the Exército do Lula Channel
“Exército do Lula” (Lula’s Army) is a WhatsApp channel with more than 3 million members. Federal deputy André Janones of Rede, a small left-leaning party, runs it.
Flávio Bolsonaro’s campaign, for the conservative Liberal Party (PL), said the channel spread false claims about him in September.
On Sunday, 11 October, Nunes Marques ordered the channel suspended in an administrative case, Brasil de Fato and InfoMoney reported. He accepted the Flávio campaign’s argument that Meta had not applied the 91-page compliance plan it gave the court in August.
“Self-regulation exists, but the case file indicates, on a preliminary view, that it was not applied here,” he wrote, according to InfoMoney. Meta declined to comment.
The same day, the TSE’s inspector-general, Justice Ricardo Villas Bôas Cueva, reversed the order and restored the channel. He asked for the case to go to the full court at its first available session, Brasil de Fato reported.
On Monday, the court’s anti-disinformation office found none of the disputed claims in posts from 2 to 11 October. It noted that some messages had been deleted, as covered in the court’s finding on the Lula channel.
“We will not accept undue interference by the electoral courts,” Lula said, according to Brasil de Fato. Nunes Marques called both campaigns to a meeting on Tuesday, 13 October; officially, the aim is to calm tempers.
Why PT Lawmakers Want Nunes Marques Investigated
Banco Master is a Brazilian bank whose former owner, Daniel Vorcaro, is at the centre of a Federal Police fraud inquiry called Compliance Zero. See the wider Banco Master case and Flávio Bolsonaro’s contacts with Vorcaro.
Deputies Rui Falcão of São Paulo and Rogério Correia of Minas Gerais filed a “notícia de fato”, a formal tip-off, with the Supreme Court. It cites suspected passive corruption, money laundering, trading on influence, malfeasance in office and membership of a criminal organisation, Correio Braziliense and Poder360 reported.
The filing points to people close to the justice and to a vote cast in a case worth billions to the bank. It asks the Supreme Court and the prosecutor-general to act, and asks for the material to go to the Senate.
That vote came on 1 October 2024 in a case brought by the Alcídia distillery against the federal government. With the Supreme Court’s Second Panel tied 2 to 2, his vote decided it for the creditors, Estado de Minas reported.
Senator Alessandro Vieira of the centrist MDB filed an impeachment request against him in the Senate on 24 September. The complaint argues that this vote contradicts his statement in a Supreme Court session that he had “never judged any case related to Master”.
Nunes Marques says Master was not a party to that case and rejects any link between his vote and the bank’s interests, Poder360 reported.
In earlier statements, Nunes Marques denied receiving money from Vorcaro or exchanging messages with him, Poder360 reported. He also said his son received no money from Master.
Both outlets stressed that the suspicions still depend on investigation. Neither the justice nor his office had publicly answered the new request in Monday’s reports.
What Prediction Markets Say
On Polymarket, an online prediction market, bettors give Flávio Bolsonaro an 87.5% chance of winning the runoff (13 October, 4:56 a.m. ET). Lula stands at 12.5%, in a market with about US$180 million in total bets.
Prediction markets · who wins the runoff
Implied chance of winning Brazil’s presidency on 25 October, from traders’ prices.
Polymarket
Flávio Bolsonaro 87.5% · Lula 12.5% (US$180 million traded)
Kalshi (regulated in the US by the CFTC)
Flávio Bolsonaro 87% · Lula 13%
As of 13 October, 5:20 am ET (10:20 Lisbon), updated every 20 minutes. Prices are bets, not polls, and can move fast.
Why we show this: prediction markets turn real-money bets into a live probability that moves within minutes of the news, which is why investors, campaigns and newsrooms in the United States now follow them closely. We show them next to polls and official results, never instead of them.
What It Means for You
For investors in Meta, the case shows Brazil’s election court using a platform’s own compliance promises as grounds for action. The order fell within hours, but the full court has still to weigh in.
For anyone exposed to Brazilian assets, the referee of the runoff is now a political target himself. His court will settle disputes over online campaigning in the 12 days left before the 25 October vote.
What Is Not Known
It is unclear which Supreme Court justice will receive the deputies’ request, or whether the prosecutor-general will open an inquiry.
How the full TSE will rule on Cueva’s decision is not yet known. Nor is the outcome of Tuesday’s meeting with the two campaigns.
More on this story: Brazil Finds No Fake News in Lula Channel; Brazil's Exército do Lula Case Tests Meta's Election Pledge; Brazil's Meta Ruling and What Comes Next Before the Runoff.
More: Brazil news in English, every day from The Rio Times.
Frequently Asked Questions
Who appointed Kássio Nunes Marques to Brazil’s Supreme Court?
Jair Bolsonaro nominated him in 2020 to replace the retired Justice Celso de Mello. The Senate confirmed him by 57 votes to 10, and he took his seat on 5 November 2020.
Since when has he led Brazil’s electoral court?
He became president of the Superior Electoral Court on 12 May 2026, succeeding Cármen Lúcia. He therefore oversees the 2026 general election, including the 25 October presidential runoff.
What is the Banco Master case?
It is a Federal Police fraud inquiry, called Compliance Zero, into Banco Master and its former owner, the banker Daniel Vorcaro. Several politicians and judges have been named in reporting on the case.
Has Kássio Nunes Marques been charged with a crime?
No. Two Workers’ Party deputies have asked the Supreme Court to investigate Nunes Marques, and a senator wants him impeached. Neither step is a charge, and he has denied receiving money from Vorcaro.
Sources: Correio Braziliense, 12 October 2026; Poder360, 12 October 2026; Brasil de Fato, 12 October 2026; InfoMoney (Estadão Conteúdo), 12 October 2026; Estado de Minas, 24 September 2026; Correio da Manhã, June 2026; Migalhas, 11 May 2026; Diario de Pernambuco (Estadão Conteúdo), 12 May 2026; Migalhas, 5 November 2020; ConJur, 5 November 2020; Poder360, 15 September 2026; A Gazeta, 21 October 2020.
This article was produced by The Rio Times’ automated newsroom system. How we use AI · Report an error · Editorial responsibility: Matthias Camenzind, Editor-in-Chief
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