Alexandre Curi, Deltan Dallagnol, Filipe Barros and Gleisi are tied in Parana's Federal Senate race, according to a Quaest poll released on Thursday.
Curi, running for Republicanos, leads with 14 percent of voter intentions in the southern Brazilian state. Dallagnol, representing the party Novo, and Barros, of the Liberal Party (PL), each recorded 11 percent, while Gleisi, of the Workers' Party (PT), received 10 percent.
With the survey carrying a margin of error of three percentage points in either direction, all four contenders sit in a statistical dead heat for the two Senate seats.
Further down the field, Dr. Rosinha of the Workers' Party and Cristina Graeml of the Social Democratic Party (PSD) each registered 5 percent. Karen Guerreiro of Missao and Marcelo Marcelino of the Workers' Cause Party (PCO) tied at 1 percent, while Joaquim do MLB of Unidade Popular did not score.
A large share of voters remains undecided weeks before the election. The survey found that 29 percent of respondents are undecided, while 13 percent intend to cast a blank ballot, annul their vote or not vote at all.
Dallagnol candidacy and court challenge
Dallagnol is currently campaigning with his bid suspended by Brazil's top electoral authority, the Superior Electoral Court (TSE). The candidate continues to contest the Senate election while awaiting a final decision from the tribunal.
Dallagnol previously led the federal prosecution task force in Operation Car Wash, the sprawling anti-corruption probe that reshaped Brazilian politics over the past decade. He won election to the Chamber of Deputies in 2022 before facing legal challenges regarding his eligibility under Brazilian electoral law.
His main rivals also bring significant party backing to the campaign. Gleisi serves as the national president of the governing Workers' Party and previously represented Parana in the Federal Senate, while Barros is a conservative federal lawmaker closely associated with the Liberal Party. Curi is an established state lawmaker who currently serves in the Legislative Assembly of Parana.
Voter certainty and poll methodology
The survey measured voter preferences for both the first and second Senate seats together, with the total summing to 100 percent because each respondent was asked to make two selections. In Brazil, two-thirds of the 81-seat Federal Senate is contested every eight years, meaning voters in each state elect two senators simultaneously in the 2026 general election.
Voter commitments remain fluid for a large segment of the electorate. While 58 percent of surveyed voters described their candidate choice as definitive, 42 percent said they could still change their vote before the election on October 4.
Quaest interviewed 804 registered voters across Parana between September 20 and 23. Commissioned by media company Grupo Globo, the poll has a 95 percent confidence level and is registered with the Superior Electoral Court under protocol PR-02802/2026.
