POLPolitics NO. ---

Brazil runoff: Lula and Flávio Bolsonaro ask court to bar each other

Flávio Bolsonaro led the October 4 first round with 47.03% of valid votes to Lula's 45.16%. Neither campaign's disqualification request had been ruled on as of October 21, and Meta says it has complied with the TSE order.

By Rowan Ashby Published 21.10.26 07:17 UTC 6 min read

Headquarters building of Brazil's Superior Electoral Court (TSE) in Brasília — Alexandresena / Wikimedia Commons / CC BY-SA 4.0 · Source

Key takeaways

Brazil votes on Sunday, October 25, in a presidential runoff between President Luiz Inácio Lula da Silva (PT) and Senator Flávio Bolsonaro (PL), after a first round on October 4 that put Flávio ahead by under two percentage points of valid votes.
In the final week, each campaign has gone to the Superior Electoral Court (TSE) seeking to knock the other out of the race, though neither request had been ruled on as of October 21.
The TSE ordered Meta to apply identical rules to both campaigns on Facebook, Instagram and WhatsApp, and raised the daily penalty for non-compliance to 1 million reais. Meta told the court on October 20 that it had complied, and it denies favouring either candidate.
Published polls describe a close race. A Quaest survey released on October 14 put Flávio at 46% and Lula at 44%, within its two-point margin of error.

What the first round settled

In the final week of the Brazil runoff, Lula and Flávio Bolsonaro have each asked the Superior Electoral Court (TSE) to disqualify the other before Sunday's October 25 vote. The TSE has ordered Meta to apply identical rules to both campaigns; Meta says it complied.

The gap was about 2.2 million votes. On October 4, the eve of the vote, a Datafolha poll had shown Lula ahead, so Flávio's first-place finish changed how both campaigns approached the runoff. TSE president Kassio Nunes Marques said the count had run normally apart from a brief delay in publishing results, which the court blamed on congestion in its results system.

First-round result and selected runoff polling
Measure	Flávio Bolsonaro (PL)	Lula (PT)	Source / date
First round, share of valid votes	47.03%	45.16%	TSE, October 4 vote
Quaest runoff poll, all respondents	46%	44%	Quaest via Reuters, fieldwork Oct 10–13, released Oct 14
Quaest runoff poll, valid votes	51%	49%	Quaest via O Povo, released Oct 14

The October 14 Quaest survey, commissioned by TV Globo, interviewed 2,154 people and has a margin of error of plus or minus two percentage points, so the gap between the candidates is statistically inconclusive. Reuters reported that 9% of respondents said they would vote blank, spoil their ballot or not vote. A second Quaest runoff survey, with fieldwork from October 17 to 20 and TSE registration BR-08535/2026, was due for release on October 21. Its results were not available when this article was written.

The fight over Meta

The biggest legal dispute of the runoff campaign is about the platforms, not the candidates directly. According to the Associated Press, Lula's campaign filed a complaint on October 15 accusing Meta, which owns Facebook, Instagram and WhatsApp, of using biased algorithms and AI restrictions that favoured Flávio Bolsonaro. AFP reported the campaign's claim that WhatsApp's AI tool restricted election content about Lula but not about his opponent.

What the court ordered

On October 15, Minister Marco Aurélio Bellizze, the TSE judge responsible for election advertising disputes, ordered Meta to apply the same rules to both candidates through the runoff, with a fine of 500,000 reais (about $100,000) for each day of non-compliance. The Rio Times reported that a majority of the court's virtual plenary backed the order on October 16. According to that report, the order:

bars Meta from reducing the reach, recommendations, search visibility or metrics of either candidate's political content, except under rules applied equally to both;
requires human review before campaign ad accounts are disabled or boosted posts blocked, and within two hours when an automated system imposed the restriction;
requires the Meta AI assistant to apply identical rules to both candidates.

The Rio Times also reported that Bellizze wrote that the ruling does not find Meta manipulated content for or against any candidate. The order is described as preventive, and the merits of the case have yet to be decided.

On October 19, AFP reported that the court found Meta had not shown compliance. The court called the original penalty "insufficient", doubled the daily fine to 1 million reais (about $200,000) and gave the company 24 hours to prove equal treatment. The AP reported that hundreds of people protested outside Meta's São Paulo office the same day.

Meta's reply

On October 20, Meta told the court that it had "completed the implementation of measures to comply with the directive from the electoral court," the AP reported. The company said the restrictions "do not affect organic posts". It described a human review system that manually checks automated blocks or limits on presidential campaign ad accounts within two hours. Meta said its recent problems were caused by technical limitations and repeated its denial of political bias or deliberate interference. AFP reported that Meta had earlier said some Lula campaign ads were switched off in error because of technical faults that were not limited to Brazil. A TSE spokesperson confirmed to the AP that the court had received Meta's response.

Dueling disqualification bids

As of October 21, both campaigns were trying to get the other candidate barred from office.

Flávio Bolsonaro's filing against Lula

Al Jazeera and AFP reported that lawyers for Flávio Bolsonaro asked the TSE on October 20 to declare Lula and Social Communications Minister Sidônio Palmeira ineligible for public office for eight years. The filing accuses them of "abuse of power" through mass WhatsApp messages sent by the government during the campaign that promoted social programmes and benefits. Flávio called the messages unlawful propaganda and asked for Lula's candidacy to be annulled. The government's response to the filing had not been reported.

Lula's planned filing against Flávio

Lula's campaign said it would ask the TSE to revoke Flávio Bolsonaro's ticket. The request is an electoral judicial investigation action (AIJE) built on the Meta allegations. According to Brazilian newspaper A Tarde, the campaign plans to argue that recommendation algorithms, AI tools and ad-review systems helped Flávio and harmed Lula, which it says amounts to misuse of social media and abuse of economic power. AFP reported on October 21, citing a campaign source, that the petition had not yet been formally filed. Meta denies favouring any candidate and says its rules apply equally to everyone.

What it means

Disqualification requests in Brazil are decided by the electoral courts after the defence has responded and the electoral prosecutor has given an opinion. That process usually takes longer than the four days left before Sunday's vote. Neither request is therefore likely to stop the vote, but either could affect what happens after it. Under Brazilian electoral law, a ruling on abuse of power can still annul a mandate or bar a candidate from office after the election.

The Meta case may matter beyond Brazil. It is one of the first times a national electoral court has ordered a global platform, during a live runoff, to show that its algorithms, ad-review systems and AI assistant treat rival candidates the same. The court has not found deliberate bias, and Meta says it has complied. Whether the court accepts Meta's response, and whether it rules on the merits before or after October 25, are the main open questions. Polls within their margins of error and a first-round gap of under two points mean that turnout and blank or spoiled ballots could decide the result.

The TSE says polls close at 5 p.m. Brasília time on October 25 and results will be published on its official results portal after that.

Frequently asked questions

When is Brazil's presidential runoff?

The runoff between Luiz Inácio Lula da Silva and Flávio Bolsonaro is on Sunday, October 25, 2026. The Superior Electoral Court (TSE) publishes results on its official portal after polls close at 5 p.m. Brasília time.

What was the first-round result?

According to the TSE, Flávio Bolsonaro won 47.03% of valid votes on October 4 and Lula won 45.16%. Neither passed 50%, so the race went to a runoff.

What did the electoral court order Meta to do?

The TSE ordered Meta to apply the same rules to both campaigns on its platforms, including reach, recommendations, ad reviews and its AI assistant. On October 19 it raised the daily fine for non-compliance from 500,000 to 1 million reais. The court has not found that Meta deliberately favoured either candidate.

How did Meta respond?

On October 20, Meta told the court it had completed the measures needed to comply. It said the restrictions do not affect organic posts and denied any political bias, blaming earlier problems on technical faults.

Can either candidate be disqualified before the vote?

Both campaigns have asked the TSE to bar the other, but neither request had been ruled on as of October 21. These cases normally take longer than the days left before the vote, and Brazilian electoral law allows abuse-of-power rulings to take effect after an election.