People's Socialist Revolutionary Party

"HASI" redirects here. For other uses, see HASI (disambiguation).

Herri Alderdi Sozialista Iraultzailea (People's Socialist Revolutionary Party) best known for its acronym HASI, that in Basque language means to begin, was a non-legal Basque political party, considered commonly to be the political branch of ETA. It always ran as part of the coalition of the Basque National Liberation Movement, Herri Batasuna, until its self-dissolution in the 1990s.