Institutional Act Number Five

AI-5 suspended most civil rights, including habeas corpus, allowed for the removal from office of opposition politicians, federal interventions in municipalities and states.

Written by then Minister of Justice Luís Antônio da Gama e Silva, it came as a response to reactions against the regime, such as a demonstration by over fifty thousand people in Rio de Janeiro protesting the murder of student Edson Luís de Lima Souto by a member of the state Military Police, the March of the One Hundred Thousand, and the denial by the Chamber of Deputies of authorization to prosecute Congressman Márcio Moreira Alves, who had called Brazilians to boycott the September 7 Independence Day celebrations.

It also aimed to consolidate the ambitions of a hardline faction within the regime which was unwilling to relinquish power in the foreseeable future.

Under the leadership of Daniel Krieger, the following Senators signed a disagreement message addressed to the president: Gilberto Marinho, Miltom Campos, Carvalho Pinto, Eurico Resende, Manoel Villaça, Wilson Gonçalves, Aloisio de Carvalho Filho, Antonio Carlos Konder Reis, Ney Braga, Mem de Sá, Rui Palmeira, Teotônio Vilela, José Cândido Ferraz, Leandro Maciel, Vitorino Freire, Arnon de Melo, Clodomir Milet, José Guiomard, Valdemar Alcântara and Júlio Leite.

[10][11] On October 13, 1978, President Ernesto Geisel allowed Congress to pass a constitutional amendment putting an end to AI-5 and restoring habeas corpus, as part of his policy of distensão (détente) and abertura política (political opening).