Morocco's King Mohammed VI said Friday that his government's proposals for autonomy for the Western Sahara had "more international support" than "the despairing manoeuvres" of its adversaries.

The Western Sahara is a former Spanish colony that was annexed by Morocco in 1975. The Algerian-backed Polisario Front is demanding independence for the region.

"In as much as international support is growing in favour of this courageous initiative, recognised by the UN as serious and credible, so our adversaries persist in their despairing manoeuvres trying in vain to block it," the king said in a broadcast to the nation.

"The obstinacy of the enemies of our territorial integrity only reassures Morocco in its march towards democracy and development", he added.

The Polisario Front has rejected the Moroccan proposal for self-government and insists on the right of the Sahrawi people to a referendum on self-determination, but it laid down its arms after a 1991 ceasefire.

The day Mohammed VI gave his speech, Spanish daily El Pais reported that a top UN envoy is doubtful a settlement can be reached on the Western Sahara and wants Madrid, Paris or Washington to intervene with Morocco and the Polisario.

The UN special envoy to the region, Christopher Ross, said in a letter obtained by El Pais that neither Rabat nor the Polisario "possess the political will to enter into genuine negotiations on the future of the Western Sahara or to give priority attention to confidence-building measures".

Ross called for help from the UN Security Council and the so-called Group of Friends that is trying to resolve the conflict -- Britain, France, Russia, Spain and the United States.