L Legislature of the Mexican Congress

The L Legislature of the Congress of the Union met from 1976 to 1979. This 50th session of Congress consisted of senators and deputies who were members of their respective chambers. They began their duties on September 1, 1976, and ended on August 31, 1979.

The senators and deputies were elected to office in the 1976 Mexican general election. The senators were elected for a period of six years (so they maintained their seat in the next legislature), and the deputies were elected for a period of three years.

Members
The composition of the 50th Congress was as follows:

Senate of the Republic
Two members were elected to the Senate from each state and the Federal District, giving a total of 64 senators. For the first time in history a senator was elected who did not belong to the Institutional Revolutionary Party (PRI). Jorge Cruickshank García had been nominated by the PPS; the PRI did not lose this seat, however, because it formed an electoral alliance with the winning party. Thus this senator posed no opposition to the PRI or the government during his term.

Number of Senators by political party
The 64 Senators forming the L Legislature were the following:

Chamber of Deputies
For the L Legislature, the Chamber of Deputies was composed of a total of 238 deputies, of whom 196 were elected by majority vote in each constituency and 41 more were deputies by party. These were allocated in proportion to the votes that the non-winning parties obtained in the districts.

The composition of the Chamber of Deputies during the 50th session of Congress was as follows:

Presidents of the high commission of the Chamber of Deputies

 * 1976–1977: Augusto Gómez Villanueva PRI Party (Mexico).svg
 * 1977–1979: Rodolfo González Guevara PRI Party (Mexico).svg
 * 1979: Antonio Riva Palacio López PRI Party (Mexico).svg

Main accomplishments
It was the 50th Congress that, in 1977, adopted the first political reforms to occur in Mexico. This reform, negotiated by Secretary of the Interior Jesús Reyes Heroles, included legal recognition of political organizations from the left, traditionally marginalized and pushed into armed struggle, especially after the events of 1968 and which degenerated into a "Dirty War" during the 1970s.

Legal reform, known formally as the Ley de Organizaciones Políticas y Procedimientos Electorales (LOPPE) (Law of Political Organizations and Electoral Procedures), defined and made possible procedures for the registration of new political parties (in 1977 legally there were only the PRI, the National Action Party) (PAN), the Popular Socialist Party (PPS) and the Authentic Party of the Mexican Revolution (PARM)). This allowed for the registration, for the first time in 40 years of the Mexican Communist Party, which was followed by the National Assembly of the Socialist Left, the Mexican Democratic Party and the Social Democratic Party.

In addition, the (LOPPE) increased the size of the Chamber of Deputies, increasing the number of electoral districts from 196 to 300, and establishing deputies by proportional representation, replacing the previous deputies by party. There would be 100 such positions, resulting in the Chamber of Deputies comprising 400 deputies.