ELA
Basque Workers’ Solidarity (in Basque : Eusko Langileen Alkartasuna (ELA), in Spanish : Solidaridad de Trabajadores Vascos (STV)) is the most influential trade union in Basque Country, having been created, as Solidaridad de Obreros Vascos, by members of the Basque Nationalist Party on June 10, 1911, in Bilbao.
Today, it has over 100,000 members