Spain had administered the Spanish Sahara since the Berlin Congress in 1884, but had announced it was pulling out of the territory. A Madrid-backed political party, the Partido de Unión Nacional Saharaui (PUNS), argued for a gradual transition to independence and demanded privileged relations between Spain and a future Western Sahara. The Polisario Front, an indigenous anti-colonial organization that was waging a guerrilla war against Spanish forces since 1973, claimed the country for its inhabitants, the Sahrawis, and demanded immediate independence.