National Directive Nucleus of the Guatemalan Party of Labour was a splinter group of the Guatemalan Party of Labour (PGT). PGT-NDN was formed in 1978, following an internal rift within PGT. An attack of the Military Commission of PGT against a police convoy provoked the split, in which 25 police officers were killed. The central leadership of the party had denied involvement in the attack. A minority accused the leadership of being ambiguous towards the armed struggle against the regime.