With the launching of the policy of national dialogue by the Belisario Betancur government in 1984, various underground left-wing groups began exploring the possibility of building up legal movements. With the social struggles in North-Eastern Colombia, the petrol workers' struggle in Arauca, and the leadership of the Spanish priest Manuel Pérez inside the movement, the National Liberation Army (ELN) began to orient itself towards non-military social struggles.
¡A Luchar! emerged from a long process of discussions and cooperation between three groups within the Colombian leftwing: ELN, Workers Revolutionary Party (PRT), and the Revolutionary Integration Movement - Free Fatherland (MIR-Patria Libre). The three parties had begun cooperating in 1984. 18 months later, ¡A Luchar! was founded at a Workers, Peasants, People's Meeting, held as a commemoration of José Antonio Galán on March 16–March 17, 1985. In its initial organization phase, ¡A Luchar! mobilized a national civic strike on June 20 against the policies of the Betancur government regarding economic liberalizations and peace negotiations. However, the build-up of ¡A Luchar! aggravated internal divisions between the 'military' and 'political' tendencies inside ELN.
In total 850 delegates took part, as well as some 1000-1500 observers.
Nelson Berrío was the main leader of ¡A Luchar!.