Founding texts

On March 26, 1991, the Argentine Republic, the Federative Republic of Brazil, the Republic of Paraguay, and the Oriental Republic of Uruguay signed, in the city of Asunción, the treaty that laid the foundations for the creation of the Southern Common Market (MERCOSUR): the Treaty of Asunción.

Initially, the Treaty provided for a provisional institutional structure, which was later amended on December 17, 1994, with the signing of the Additional Protocol to the Treaty of Asunción on the Institutional Structure of MERCOSUR (Protocol of Ouro Preto). This established the definitive institutional structure, consisting of three decision-making bodies and three non-decision-making bodies.

Over the years, in response to the different stages of the integration process, other bodies have been created. Going beyond the economic and trade perspective of the initial stage, these bodies address other areas of a social and citizen-oriented nature. This is the case of the  MERCOSUR Institute for Public Policies on Human Rights (IPPDH), the  MERCOSUR Social Institute (ISM), the  Parliament of MERCOSUR (PARLASUR), the  MERCOSUR Secretariat (SM) and the  Permanent Review Tribunal (TPR).

Furthermore, under Article 20 of the Treaty of Asunción, which allows the accession to MERCOSUR of Member States of the Latin American Integration Association (ALADI), the integration process has also been marked by the incorporation of new members.

Once signed and incorporated into the domestic legal systems of the States Parties, the Protocol of Accession of the Bolivarian Republic of Venezuela to MERCOSUR, dated July 4, 2006, made the Bolivarian Republic of Venezuela a full member of the regional bloc*.

Subsequently, on July 17, 2015, the Protocol of Accession of the Plurinational State of Bolivia to MERCOSUR was signed by all the States Parties. Bolivia** deposited its Instrument of Ratification in July 2024 and has up to four years to incorporate the bloc’s regulatory framework.

MERCOSUR also has  Associated States, that is, those members of ALADI that have concluded partial agreements with MERCOSUR and have expressed their intention to obtain such status. This is the case for Chile, Colombia, Ecuador, and Peru.

Similarly, since 2004 it has been possible for Associated States to include those States or economic areas of Latin America that sign treaties with MERCOSUR under Article 25 of the 1980 Treaty of Montevideo.  This is currently the case for Guyana and Suriname.

*The Bolivarian Republic of Venezuela is suspended from all the rights and obligations inherent in its status as a State Party to MERCOSUR, in accordance with the provisions of the second paragraph of Article 5 of the Protocol of Ushuaia.

** Plurinational State of Bolivia, new State Party, in accordance with Decision 20/19.

The integration process is also characterized by a strong commitment to democracy, expressed in the Protocol of Ushuaia on Democratic Commitment in MERCOSUR, the Republic of Bolivia, and the Republic of Chile, signed on July 24, 1998, and in force since 2002.

Significant progress has also been made in other legal and institutional areas, particularly in dispute settlement. In this regard, the Protocol of Olivos for the Settlement of Disputes in MERCOSUR, signed on February 18, 2002, entered into force on January 1, 2004, repealing the previous Brasilia Protocol.

The Protocol of Olivos created the TPR, a judicial body composed of permanent arbitrators, each a national of a MERCOSUR member.  In addition to the three disputes resolved under the current system, the four advisory opinions issued by the TPR are also noteworthy, as they contribute to the uniform application of regional law.

Regarding regional citizen participation, the institutional structure created by the Protocol of Ouro Preto provided for the existence of a Joint Parliamentary Commission.

On December 8, 2005, the Constitutive Protocol of the MERCOSUR Parliament was signed, entering into force in early 2007 as a body representing citizens’ interests. PARLASUR replaced the Joint Parliamentary Commission, and under the 2009 Political Agreement, a principle of attenuated proportionality was established for its composition. It was foreseen that by 2020, all PARLASUR representatives would be elected by direct universal suffrage.

Below are the legal instruments that make up MERCOSUR’s founding regulatory framework and reflect the most important institutional milestones in these years of regional integration.