AI-5

The Ato Institucional Número Cinco – AI-5 (English: Institutional Act Number Five) was the fifth of seventeen major decrees issued by the military dictatorship in the years following the 1964 coup d'état in Brazil. Institutional Acts were the highest form of legislation during the military regime, given that, issued on behalf of the "Supreme Command of the Revolution" (the regime's leadership) they overruled even the Nation's Constitution, and were enforced without the possibility of judicial review.

AI-5, the most infamous of all Institutional Acts, was issued by President Artur da Costa e Silva on December 13, 1968. It resulted in the forfeiture of mandates, interventions ordered by the President in municipalities and states and also in the suspension of any constitutional guarantees which eventually resulted in the institutionalization of the torture commonly used as a tool by the State.

Written by then Minister of Justice, Luís Antônio da Gama e Silva, it came as a response to earlier events such as a march of over fifty thousand people in Rio de Janeiro to protest against the murder of student Edson Luís de Lima Souto by a member of the Military Police of Rio de Janeiro, the March of the Hundred Thousand, and the decision of the Chamber of Deputies denying authorization to prosecute Congressman Márcio Moreira Alves, which called Brazilians to boycott the celebrations of September 7 (Independence of Brazil). It also aimed to consolidate the ambitions of a group inside the military, known as "hardline", unwilling to give the power back to the civilians anytime soon.

The immediate consequences of the Institutional Act Number Five were:

The AI-5 did not silence a group of Senators from ARENA, the political party created to give support for the dictatorship. 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.

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