Brazil's conservative and right-wing parties posted their strongest congressional performance in decades in Sunday's general elections, securing a majority in the Chamber of Deputies while also maintaining a majority in the Senate.

The Liberal Party, led by Senator Flavio Bolsonaro, emerged as the largest party in the 513-member Chamber of Deputies, increasing its representation from 99 seats in 2022 to 121 seats. The broader right-wing bloc, made up of the PL and roughly 20 other parties, is expected to hold 276 seats when the new Congress takes office in February 2027.

The result gives the right a clear majority in the lower chamber. By comparison, the left-wing bloc, including President Luiz Inácio Lula da Silva's Workers' Party and several other leftist parties, will hold a combined 124 seats. Another 113 seats will belong to lawmakers from centrist parties.

The PL's 121 seats also represent the largest parliamentary group held by a single Brazilian party since the Brazilian Democratic Movement won 108 seats in the 1990 elections, shortly after Brazil's return to democracy.

The right's gains extend to the Senate, where conservative parties are set to control 49 of the 81 seats. The PL is expected to hold roughly one-third of those conservative seats.

The congressional results come alongside a presidential runoff scheduled for Oct. 25 between Flavio Bolsonaro of the PL and incumbent President Luiz Inácio Lula da Silva of the left-wing Workers' Party. The election will determine who occupies the presidency as the new congressional majority takes office.

Several members of the Bolsonaro family were also elected to Congress. Former President Jair Bolsonaro, who remains a major figure within Brazil's conservative movement, is currently serving a 27-year prison sentence following his conviction on charges described by Brazilian authorities as crimes against democracy.

The new congressional balance could have significant consequences for legislation and oversight of the executive branch. Under Brazilian law, ordinary legislation generally requires a simple majority, while certain measures require higher thresholds. A simple majority is also sufficient to override a presidential veto.

The Senate holds additional constitutional powers, including the authority to conduct impeachment trials involving Supreme Court justices accused of crimes of responsibility. The process requires an initial vote to move forward and a two-thirds majority, or 54 of the 81 senators, for removal.

A local think tank survey cited by CNN Brasil found that 54 senators who will serve in 2027 have already expressed support for impeaching Supreme Court justices. Conservative lawmakers have repeatedly sought impeachment proceedings against Supreme Court Justice Alexandre de Moraes in recent years.

The new congressional majority could therefore give Brazil's right-wing parties substantially more leverage over legislation, presidential vetoes and potential judicial impeachment proceedings once the new lawmakers take office next year.

The congressional results do not, however, determine the presidency. That contest will be decided separately in the Oct. 25 runoff between Bolsonaro and Lula.