The essay focuses on the complex link between the Partido Nacionalista Vasco (PNV) and the reference workers’ organization of the Basque national movement, Solidaridad de Obreros Vascos (Sov), since 1933 Solidaridad de Trabajadores Vascos (STV). By examining periodical and archival sources, the author raises questions about the real nature of the relations between political nationalism and labor nationalism since 1911, year of Sov foundation, up to the outbreak of the Spanish civil war, in 1936. The basic thesis is that, despite the close dependence between party and trade union in the 1910s, since the early 1920s and particularly during the Second Republic (1931-1936), the nationalist workers’ organization gradually enfranchised itself from the traditional party tutelage. In the 1930s, Sov-Stv became a modern mass trade union and was affected by an intensive class radicalization process that allowed to assume an autonomous political and ‘worker’ identity.
Keywords: Solidaridad de Obreros Vascos (SOV), Solidaridad de Trabajadores Vascos (STV), Partido Nacionalista Vasco (PNV), Agrupación Vasca de Acción Social Cristiana (AVASC), Basque nationalism, Second Republic