The decision stems from cases filed by the Liberal Party (PL) and Socialism and Freedom Party (PSOL), as well as the Attorney General’s Office (AGU), regarding the legality of the IOF hike. While Mr. Moraes acknowledged the executive branch’s authority to adjust tax rates, he expressed concern over the “nature” of the recent increase.

“There is a serious and well-founded doubt about whether the presidential decree was used to adjust the IOF for purely fiscal purposes. In a preliminary assessment, this is enough to consider a potential abuse of power. If the president’s autonomous decrees are driven by a deviation of purpose, they may violate the principle of proportionality,” Mr. Moraes wrote.

He granted a preliminary injunction suspending Executive Decrees 12.466/2025, 12.467/2025, and 12.499/2025, as well as Legislative Decree 176/2025. The decision will now be sent to the full court for review, though no date has been set.

Allies with ministries also filed suit

In addition to the actions brought by the PL, PSOL, and AGU, a fourth case was filed Thursday night (3) by parties that hold ministerial positions in the Lula administration. These parties are asking the STF to declare constitutional the legislative decree that overturned the IOF increase.

Among the parties behind this request are Brazil Union, Progressives, and Republicans, which together control five ministries, including Tourism, Communications, Social Development, Sports, and Ports and Airports. Also joining the suite are Brazilian Social Democracy Party (PSDB), Solidarity, Democratic Renewal Party (PRD), Podemos, and Avante. They argue that “Congress acted properly in blocking measures that raised taxes without following the legislative process.”

Court battle deepens political crisis

The AGU’s move to file a case with the STF on Tuesday (1) to restore the IOF hike further strained relations between the Lula government and Congress. Lawmakers, particularly congressional leaders, were already upset over aggressive messaging on social media by the Workers’ Party (PT), which included AI-generated videos portraying Congress as “the enemy of the people.”

These attacks, part of a broader “rich vs. poor” narrative pushed by the government, specifically targeted Chamber Speaker Hugo Motta (Republicans of Paraíba). The polarization strategy had already drawn criticism from lawmakers and is expected to further deteriorate relations with the Legislature. In response, the Brazil Union-Progressives federation released its own video rebutting the campaign over the weekend.

Yesterday, before his party filed its own case against the executive, Congressman Arthur Lira (Progressive Party, PP, Alagoas), speaking at an event in Lisbon, called for de-escalation among all branches of government. “Everyone needs to take a step back—the Legislative, Judiciary, and Executive. They need to sit at the table and resolve this without letting tensions get this high,” said Mr. Lira, who previously served as Speaker of the Chamber.