BUENOS AIRES – WikiLeaks founder Julian Assange, former Brazilian President Dilma Rousseff and US linguist Noam Chomsky were among the more than 200 notables who signed an open letter to the Argentine government requesting the release of political activist Milagro Sala, who has been jailed for 18 months.

The document was published on Monday by the Committee for the Freedom of Milagro Sala.

“We have launched a petition to President (Mauricio) Macri that he comply with the resolution of the United Nations Working Group (on Arbitrary Detention) and release Milagro Sala,” committee coordinator Mara Brawer told a press conference outside the federal courthouse in Buenos Aires.

An international pressure campaign can have an impact on Macri’s conservative government, she said.

“The petition is open, but we already have the signature of Dilma Rousseff, (Argentine ex-President) Cristina Fernandez de Kirchner, of Julian Assange, of Noam Chomsky and of the progressive bloc in the European Parliament and of more than 200 domestic and international figures,” Brawer said.

Sala, an indigenous woman, is a member of the Southern Cone Common Market (Mercosur) parliament and a leader of the social organization Tupac Amaru.

The petition notes that the Inter-American Commission on Human Rights, the Organization of American States, Amnesty International, and Human Rights Watch, among other parties, have urged Argentina “to end the arbitrary imprisonment of Mrs. Milagro Sala.”

Sala, in her work with Tupac Amaru, had a role in administering a grant from Argentina’s previous center-left government to build low-income housing in the impoverished northern province of Jujuy.

She was detained on Jan. 16, 2016, during a protest against provincial Gov. Gerardo Morales, a political ally of Macri.

Prosecutors later accused Sala, 53, of mishandling the grant money and she has remained behind bars for 18 months.