In 1977 , the Marxist Workers ' League , associated with the Organising Committee for the Reconstruction of the Fourth International , joined the party . In the following years , other small groups of Trotskyists also joined the PRT , but the group associated with Moreno left in 1979 to form the Socialist Workers ' Party . ( Partido Obrero Socialista ) ( POS ) From their base in the 1968 student movement , the PRT grew quickly , soon gaining bases of support among some telephone , electrical , nuclear , and hospital workers . By the 1980s , it was the largest far-left party to challenge the ruling Institutional Revolutionary Party ( PRI ) . In 1981 , the federal government recognized the PRT as an official nationwide party . In the 1982 general elections , it was also the first Mexican party to raise gay rights as a campaign issue ; the party fielded several openly gay candidates for the Chamber of Deputies . It also entered informal alliances with the other main party on the far left , the United Socialist Party of Mexico ( PSUM )
1968 student movement
Tlatelolco massacre
Workers' Revolutionary Party (Mexico)