The Moroccan Authenticity and Modernity Party (AMP), grouping King Mohammed's staunchest supporters, selected leading Western Sahara figure Mohamed Sheikh Biadillah as its leader on Sunday, the party said.

Western Sahara was annexed by Morocco in 1975 after the colonial power Spain withdrew, but the Sahrawi Polisario Front continues to demand independence, although a ceasefire has been in force since 1991. A United Nations-sponsored peace process is deadlocked.

The AMP is widely seen as the brainchild of King Mohammed's former top aide Fouad Ali Himma, who stepped down in 2007 as Morocco's top security official to become its most influential politician.

Its focus is on countering both the influence of opposition Islamists across Morocco and the Polisario Front.

Biadillah, a 60-year-old former government minister, was elected unanimously at end of the AMP's first congress, in Bouznika, outside Rabat, the party said.

AMP is controlled by the Movement of All Democrats, a civic association that wields huge influence as it groups top ministers, businessmen and intellectuals.

The new U.N. envoy to Western Sahara, Christopher Ross, met Polisario leaders on Sunday in the western Algerian town of Tindouf, where the movement has its headquarters.

Ross, who held talks with King Mohammed and other top government officials on Saturday, is touring the region to try to unblock the stalemate over Western Sahara.