PGT-PC was formed in 1978 as a split from the Guatemalan Party of Labour (PGT).

They had belonged to the Rebel Armed Forces (FAR), but had left FAR to join PGT.

In the early 1980s PGT-PC expelled Carlos Quinteros (nom de guerre: Miguel).

Quinteros had joined PGT-PC after having participated in the formation of the National Directing Nucleus of PGT (PGT-NDN).

He provided information to the military about the whereabouts and identities of leaders and key cadres of PGT, PGT-NDN and PGT-PC.