Oposición Sindical Obrera ("Working Class Union Opposition", abbreviated OSO) was a clandestine

trade union A trade union (labor union in American English), often simply referred to as a union, is an organization of workers intent on "maintaining or improving the conditions of their employment", ch. I such as attaining better wages and benefits ( ...

movement in

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

. OSO was originally tied to the

Communist Party of Spain The Communist Party of Spain ( es, Partido Comunista de España; PCE) is a Marxist-Leninist party that, since 1986, has been part of the United Left coalition, which is part of Unidas Podemos. It currently has two of its politicians serving as ...

(PCE). Many of its members participated in '' vertical union'' elections of 1963 in order to infiltrate the official regime union, including

Marcelino Camacho Marcelino Camacho Abad (January 21, 1918 – October 29, 2010) was a Spanish trade unionist and politician. He was a founding member of Comisiones Obreras (CCOO) and its first Secretary-General, holding this position between 1976 and 1987, and a c ...

. OSO is considered the precedent for the

Workers' Commissions The Workers' Commissions ( es, Comisiones Obreras, CCOO) since the 1970s has become the largest trade union in Spain. It has more than one million members, and is the most successful union in labor elections, competing with the Unión General de ...

(CCOO). In the mid 60's the PCE abandoned the OSO in favour of the more successful

CCOO The Workers' Commissions ( es, Comisiones Obreras, CCOO) since the 1970s has become the largest trade union in Spain. It has more than one million members, and is the most successful union in labor elections, competing with the Unión General de ...

. When the PCE abandoned the organization the PCE (m-l), a 1964

maoist Maoism, officially called Mao Zedong Thought by the Chinese Communist Party, is a variety of Marxism–Leninism that Mao Zedong developed to realise a socialist revolution in the agricultural, pre-industrial society of the Republic of Ch ...

split of the PCE took over the OSO and transformed it in its affiliated union. OSO disappeared in 1977 when it was transformed in the Asociación Obrera Asambleista (AOA).Laiz, Consuelo (1994).
La izquierda radical en España durante la transición a la democracia
'.

Madrid Madrid ( , ) is the capital and most populous city of Spain. The city has almost 3.4 million inhabitants and a metropolitan area population of approximately 6.7 million. It is the second-largest city in the European Union (EU), and ...

Universidad Complutense de Madrid The Complutense University of Madrid ( es, Universidad Complutense de Madrid; UCM, links=no, ''Universidad de Madrid'', ''Universidad Central de Madrid''; la, Universitas Complutensis Matritensis, links=no) is a public research university lo ...

. pp. 63–225. .

References

* Wilhelmi Casanova, Gonzalo (2014).
Izquierda revolucionaria y movimientos sociales en la Transición. Madrid, 1975-1982.
'

Universidad Autónoma de Madrid The Autonomous University of Madrid ( es, Universidad Autónoma de Madrid; UAM), commonly known as simply la Autónoma, is a Spanish public university located in Madrid, Spain. The university was founded in 1968 alongside the Autonomous Universi ...

. pp. 29–520. Trade unions in Spain {{Spain-org-stub