The ruling has escalated tensions between branches of government. Opposition lawmakers criticized Mendes, accusing him of overstepping legislative powers to shield the Supreme Court.

Senate President Davi Alcolumbre of the center-right Brazil Union Party, Amapá responded with outrage, saying the decision encroaches on the powers of the Legislature. Alcolumbre had already expressed frustration with the executive branch over the nomination process for a Supreme Court vacancy.

On Wednesday evening, the Office of the Attorney General (AGU) filed a request asking Justice Mendes to reconsider, in a document signed by Jorge Messias, the government’s nominee for the Court.

By issuing a solo ruling, the Supreme Court appears to be preempting a possible shift in the Senate’s composition in 2027 that could favor allies of former President Jair Bolsonaro. Within the Court, there is concern that depending on the results of next year’s elections, the Senate could begin approving impeachment requests in retaliation for judicial rulings.

In October, Valor had already reported that Mendes was preparing to issue an individual ruling tightening the rules for impeaching Supreme Court justices.

Justice Mendes is the rapporteur for two cases challenging Brazil’s 1950 Impeachment Law. The Solidarity Party and the Brazilian Association of Magistrates (AMB) argue that only the prosecutor general should be able to file impeachment charges and that removing a justice should require a two-thirds Senate vote.

The Office of the Prosecutor General supported this interpretation. The full Supreme Court will vote on whether to uphold Mendes’s ruling during a virtual session scheduled for December 12.

Opposition lawmakers responded by considering the revival of a bill authored by Senate Speaker Rodrigo Pacheco (Social Democratic Party, Minas Gerais) to revise impeachment rules for various authorities, including Supreme Court justices.

Constitutional amendment

There is also talk of proposing a constitutional amendment to reinstate sections of the Impeachment Law that Mendes suspended, most notably, the provision that allows any citizen to file an impeachment request against a Supreme Court justice.

“Brazil already has a clear law: any citizen can report Supreme Court justices for crimes of responsibility. It’s always been that way. But in a solo decision with no constitutional basis, Justice Gilmar Mendes decided to rewrite the law, restrict the rights of the people, and infringe on the Senate’s authority,” said Congressman Nikolas Ferreira (Liberal Party, Minas Gerais) on social media. He also accused Mendes of “judicial activism” and said he plans to file a constitutional amendment to preserve the current rules.

Lawmakers from the Liberal Party, New Party, and Republicans Party also condemned the ruling. Members of these parties have filed impeachment requests against Mendes and, more recently, against Justice Alexandre de Moraes.

Senator Eduardo Girão (New Party, Ceará) said Mendes is acting in his own interest. “The justice had already expressed his views in multiple interviews and should have recused himself. He and Moraes top the list of justices facing impeachment requests in the Senate. Now it’s a matter of either shutting down the Senate altogether or responding urgently and forcefully.”

‘Hijacking Parliament’

In a written statement, Congressman Zucco (Liberal Party, Rio Grande do Sul), leader of the opposition in the Lower House, said the Supreme Court is “trying to hijack Parliament’s prerogatives and silence citizens.” He called the ruling “a soft coup against the system of checks and balances, furthering the concentration of power Brazil has seen in recent years.”

Romeu Zema, governor of Minas Gerais and a potential presidential candidate from the New Party, said the Supreme Court “shredded the Constitution” and created “rules to protect itself.” He said the decision worsens the country’s “democratic crisis.” “The law should apply to everyone, and the Constitution itself states that it’s the Senate that should act as a check on Supreme Court abuses,” he wrote on social media.

Supreme Court justices interviewed by Valor said Congress has every right to legislate on the matter. However, they believe the existing Impeachment Law could not remain unchanged, as many recent requests have been driven by political motives and used as retaliation for Court decisions that upset lawmakers. They cited recent rulings involving former President Bolsonaro’s arrest and decisions on congressional amendments as examples.

In his ruling, Mendes said impeachment is an “extraordinary measure” and that Supreme Court justices are being targeted for removal simply because of their rulings.

“When the judiciary is subject to abusive external pressure, such as impeachment threats based on the substance of judicial decisions, it loses its ability to serve as a legitimate and impartial counterweight to the other branches of government, becoming just another tool for political groups,” he wrote.

Political intimidation

“It’s important to stress that using impeachment abusively or as a political weapon is not merely an attack on individuals, it undermines the very structure of the rule of law. When justices are removed or threatened based on political motives, it sends the message that the judiciary cannot or should not fulfill its constitutional role.”

Mendes said impeachment threats erode public trust in “one of the country’s most vital institutions” and serve as a form of intimidation aimed at subordinating the judiciary to the interests of the other branches, thereby weakening “constitutional oversight, the protection of fundamental rights, the containment of power abuses, and the accountability of public officials involved in wrongdoing.”

Prior to the decision, any citizen could file a formal request for impeachment with Congress. Mendes said that authority should rest solely with the prosecutor general.