It presented twice a common candidate, Salvador Allende, for the 1958 and the 1964 presidential elections.

The FRAP succeeded to the FRENAP (Frente Nacional del Pueblo, People's National Front), formed the following year by a coalition of the Socialist Party (PS) and the Communist Party (PCCh).

The new coalition, created on February 28, 1956, as a platform of movements struggling for an "anti-imperialist, anti-oligarch and anti-feudal program."

Apart from the Socialist and the Communist parties, the FRAP included: the Popular Socialist Party (until its merger in 1957 with the PS); the People's Democratic Party (Partido Democrático del Pueblo), which merged in 1960 with the PS to form the PADENA (which in turn withdrew itself from the FRAP coalition in 1965); the Vanguardia Nacional del Pueblo (National Vanguard of the People), which had been created in 1958 from a merger of minor groups such as the Labour Party (1953) and others; and the Social Democrat, founded in 1965.

For the first one, the coalition was a "Workers' Front", formed exclusively of working classes' parties struggling to defend their interests, while for the latter, it was rather a "National Liberation Front," that is a legal means to accede to power through elections, in alliance with "bourgeois parties" such as the Radical Party and the Christian Democrat Party who would united in a common national emancipation program and social and political democratization program.