The Republic of Cuba is, according to its constitution, a socialist state organised as a Republic. The Constitution (adopted in 1976, amended 1992, 2002 and 2019) ascribes the Cuban Communist Party the role of the “highest leading force of society and of the state”. The President of the Council of State is the head of the government and presides over the Council of Ministers, the legislative branch is formed by the National Assembly of People’s Power; the People’s Supreme Court is the highest judicial body.

Cuba’s legal system follows the civil law tradition, adapted to the socialist system. The Constitution’s hierarchy is above any other norm from the country. Key features of the Constitution include the recognition of sovereignty being nontransferably with people — exercised “directly and via Assemblies of People’s Power and other organs of the State that are derived from them” (article 3) — , strict regulation of personal property, and government control of the economy. The National Assembly of People’s Power, according to article 102, is the supreme organ of the power of the State, representing the entire population and expressing their sovereign will. It is the only organ with legislative and constituent power within the Republic (article 103). Article 108 establishes that the duties of  the National Assembly of People’s Power include “a. To agree upon reforms to the Constitution, according to that which is established in Title XI; b. To issue a general and obligatory interpretation of the Constitution and the laws, in necessary cases, in correspondence with the procedure prescribed by the law; […]”. Article 120 of the Constitution further establishes a Council of State under the National Assembly of People's Power. The Council of State’s duties include: “a. To ensure the implementation of the Constitution and the laws; b. To give a general and obligatory interpretation, in necessary cases, for the laws in force[…]” (article 122). 

Members of the National Assembly are elected by direct and proportional vote for a period of five years that can be extended under special circumstances. Some National Assembly members are elected to form the Council of State, which is the highest representative body of the state. The Constitution is the supreme law of the country, followed by Acts (adopted by the National Assembly) and decree-laws (issued by the Council of State between the sessions of the National Assembly and subject to subsequent ratification by the latter), and implementing legislation – decrees and agreements of the Council of Ministers, regulations, resolutions and other general provisions of the national state bodies. Climate legislation can be proposed by members of the National Assembly; the Council of State; the Council of Ministers; the commissions of the National Assembly of People’s Power; the Central Organisation of Cuban Trade Unions and the national offices of the other social and mass organisations; and at least 10, 000 citizens eligible to vote. Laws and resolutions (excluding Constitutional reforms) are adopted by the National Assembly by a simple majority vote and go into effect on the date determined by those laws, after signature by the president of the National Assembly. They are published in the Official Gazette of the Republic.