Led by the rural schoolteacher Lucio Cabañas, the PdlP – through its armed wing, the Peasants' Justice Brigade (Spanish: Brigada Campesina de Ajusticiamiento) – waged guerrilla warfare against the Mexican government in the mountains of Guerrero.

This took place in the context of the Dirty War's first beginnings, a conflict between the Institutional Revolutionary Party government and various urban and rural left-wing movements which would last roughly between the Tlatelolco massacre in October 1968 and the late 1970s, and a long period of social unrest in the country.

As a result, Cabañas was forced to escape into the mountains of Guerrero State, joining the guerrilla Genaro Vázquez Rojas, where the Party of the Poor and the Peasants' Justice Brigade would remain active for almost a decade.

In the Summer of 1973, Cabañas told an assembled group of urban and rural guerrillas: "The way to make a revolution will not be taught by Cuba... China, the Soviet Union, or any other country.

[9] During its years operating as a guerrilla movement, the Party of the Poor and the Peasants' Justice Brigade engaged in a number of criminal activities in addition to fighting government forces directly, among them kidnapping and robbery.

According to the retired Major Elias Alcaraz, who participated in the anti-guerrilla campaign, the PdlP frequently executed captured soldiers, and once killed a bridegroom at his wedding because the bride had refused to marry one of the rebels.

[10] Starting on orders from President Gustavo Díaz Ordaz, the Mexican Army took steps to suppress the revolutionary movement growing in the mountains, which over time grew increasingly heavy.

American embassy reports reflected the perception that the regime's failure was due not simply to poor military engagement, but also because of the vast support for the PdlP found among the rural peasantry.

[12] On 30 May 1974, during the political campaign for the July 1970 Mexican general election, the Party of the Poor kidnapped Figueroa – who had previously publicly dared Cabaña and the PdlP to take him – and four of his aides.

[6][16] Lucio Cabaña has become hugely popular among certain parts of the Mexican left in recent years, an icon in the vein of Ernesto "Che" Guevara and Subcomandante Marcos.

At least a thousand people crowded in the streets to commemorate the anniversary of his death on 2 December, when his remains were placed in an unfinished obelisk in Atoyac de Álvarez's central plaza, a monument constructed without official permission.

[26] As part of the ongoing criminal conflict in Mexico, Isabel Anaya Nava, the widow of Lucio Cabañas, was gunned down by two armed men in Guerrero on 3 July 2011.