One of the founders of MAP-ML, Marvin Ortega, had belonged to the national leadership of FSLN. MAP-ML built up a militant trade union activism and in urban areas had its own armed militias, Milicias Populares Antisomocistas (MILPAS). In the struggle against the Somoza regime, MILPAS forces fought under the command of the FSLN. When Albania broke with China, the MAP-ML followed Albania. MAP-ML was generally critical against the mixed economy during the FSLN government. MAP-ML was the only party that voted against the Sandinista constitution in the National Assembly.