Brazilian parties challenge seat distribution method in Supreme Court

The PDT, joined by the Missão, PSDB, and Avante parties, has filed a petition with the Brazilian Supreme Federal Court (STF) to participate in a lawsuit challenging the current method for distributing legislative seats.

The legal action, which is being rapporteur by Minister Gilmar Mendes, questions the calculation used for electoral leftovers, known as the largest averages method. The PDT argues that the current formula violates the principle of political plurality by allowing large parties and federations to secure additional seats even when individual candidates from smaller parties receive significantly higher vote counts.

As an example, the PDT cited 196 cases from the recent elections where federal deputy candidates received more votes than the last elected official in their state but failed to secure a seat. The proposed change aims to redistribute seats in a way that would likely benefit smaller political parties while reducing the number of seats held by major parties such as the PT and PL. The parties are seeking an urgent injunction to ensure these changes are implemented before the inauguration of elected officials in January 2027.