[5][7] The civil government of Madrid had prohibited the group from holding the congress, citing concerns about disturbances to the 'public order'.

[7] The organization identified itself as a class-based union, seeking to engage in class struggle.

Five other secretariat members were elected; Jesús San Martín, Luis Royo, Pedro Cristóbal, Paco Esteban and María del Carmen Fraile.

[14] In the 1978 trade union elections SU raised the slogan "Un frente común por el pan, el trabajo y la libertad" ('A common front for bread, work and freedom').

[17] According to the official count, SU had won 269 delegates out of a total of 2,614 (becoming the largest trade union in the fray).

However a count made by Diario de Navarra presented different numbers, putting SU at 432 seats (15.23%, just behind CC.OO.).

The dias carried the portrait of Joaquín Macías, a SU leader from Badajoz that had died in an accident.

A number of international delegations visited the congress, from Germany, France, Argentina, Italy and Portugal.

Instead the majority of the SU leadership proposed taking part in unity processes from below, such as the Confederación Sindical Galega.

[31] SU applied for membership in the European Trade Union Confederation in 1980, but this request was denied as the organization was perceived as lacking representativity amongst workers in Spain.

[33] SU and CSUT did not launch campaigns of their own ahead of the 1980 trade union elections.

[34] SU continues to exist in places like Huelva, Madrid, Cantabria and Barcelona.