CM-LP was formed in March 1964 by a group led by Francisco Martins Rodrigues.
[2] Martins, who was a Central Committee Member of the Portuguese Communist Party, had split from PCP in January the same year.
In 1968 one section, representing most of the leadership that was not jailed, started the publication O Comunista.
This group later merged into the Portuguese Marxist-Leninist Communist Organization (OCMLP).
In 1969 a second conference of another tendency is held inside Portugal, through the initiative of Eduíno Vilar.