FRI was formed at a national conference of leftwing forces, held in
La Paz April 23, 1978. The meeting was organized by an initiative committee (led by Dr. Guido Perales Aguilar as permanent secretary). The founding of FRI in April 1978 was a formalization of an already existing informal cooperation between different political groups. FRI was composed of the
Communist Party of Bolivia (Marxist–Leninist) (PCB(ML)),
Revolutionary Party of the Nationalist Left (PRIN),
Revolutionary Party of the Workers of Bolivia (PRTB), POR-Combate, Vanguardia Comunista del POR (the latter two were
Trotskyist groups) and an independent grouping led by .
POR-Masas was blocked from joining FRI. and politically FRI was under the control of PCB(ML).
Lidia Gueiler Tejada was the vice president of FRI. The declaration of principles of FRI reads that "FRI is the political instrument of the masses, which enables the accumulation of forces in order to defeat the dictatorship, impose democratic freedoms and achieve national liberation." ==1978 and 1979 elections==