The Polisario Front, Western Sahara's independence movement, on Sunday said it was severing ties with Spain after Madrid backed Morocco's plan giving autonomy to the former Spanish colony.
Spain has supported the autonomy plan as a way to resolve a long-running dispute over Western Sahara, which Morocco considers as its own territory.
But the Polisario, backed by Algeria, has rejected the autonomy proposal and wants an independence referendum.
The Polisario said the plan aimed to legitimise the annexation of Western Sahara "ignoring the inalienable rights of the Saharawi people to self-determination and independence."
Last month, Spain told Morocco it considered the autonomy proposal for Western Sahara was "serious, credible and realistic."
Spain's backing for Morocco's plan has helped to end a year-long diplomatic crisis between the two countries.
Moroccan-Spanish ties had soured when Spain admitted Polisario leader Brahim Ghali in April last year for medical treatment, without officially telling Rabat.
Madrid's policy shift in favour of Morocco's plan was criticised by lawmakers in Spain.
(Reporting by Jessica Jones. Editing by Jane Merriman)
