Madrid  - United Nations Secretary-General Ban Ki-moon has not renewed the mandate of Peter van Walsum, his personal envoy for Western Sahara, who was criticized by the Western Saharawi independence movement Polisario Front, the Spanish daily El Pais reported Thursday.

The Dutch diplomat, whose mandate expires this month, confirmed the report in an article he wrote for El Pais.

Van Walsum, 74, was appointed in 2005 as successor to former US secretary of state James Baker, who resigned in 2004 over the difficulties in solving one of the UN's longest-running conflicts.

Polisario has sought the independence of Western Sahara since it was annexed by Morocco after the colonial power Spain withdrew from there in 1975.

The UN brokered a ceasefire to a 15-year war in 1991, but the planned referendum on independence was never staged because of opposition from Morocco, which quarrelled with Polisario over who would be allowed to vote.

Van Walsum came to the conclusion that although Polisario's demands were legitimate, independence was not a realistic goal, because the UN Security Council would not force Morocco to comply with the referendum plan.

There was a risk of creating false hopes and of prolonging the status quo for 160,000 Saharawi refugees languishing in Algerian camps, the diplomat argued.

It would be wiser for Polisario not to insist on "total independence," van Walsum writes in El Pais. Morocco is offering Western Sahara autonomy instead of independence.

Van Walsum's stance angered Polisario, which accused him of being pro-Moroccan and urged Ban to sack him. The envoy had "disqualified himself," El Pais quoted Polisario leader Mohammed Abdelaziz as writing to the secretary-general.

Van Walsum's departure left the Western Sahara conflict in a "dead end" once again, the daily commented. (dpa)