France has backed Morocco's autonomy plan for the disputed Western Sahara, shifting a decades-old position and adding itself to a growing list of countries to align with Morocco as a United Nations-mediated peace process remains stalled.

In a letter to King Mohammed VI, France’s President Emmanuel Macron called the plan that Morocco proposed in 2007 to offer the region limited autonomy under its sovereignty that “only basis” to solve the conflict. The shift deals a blow to the pro-independence Polisario Front, which has for decades claimed to be the legitimate representative of the indigenous Saharawi people.

“The present and future of Western Sahara fall within the framework of Moroccan sovereignty,” Macron wrote in a letter made public on Tuesday. “France intends to act consistently with this position at both national and international level.”

France's departure from its historic position is a major victory for Morocco and follows similar shifts from the United States, Israel, Spain and a growing list of African nations which Morocco aims to deepen trade ties.

The move was preemptively rebuked by both Morocco’s regional foe Algeria and the Polisario Front in the days leading up to the publication of letter.

The Polisario’s Mohamed Sidati accused France of acting at odds with international law and backing Moroccan expansionism as its influence wanes throughout Africa.

“Whatever hardships Morocco tries to impose on us with the support of France, the Sahrawi people will continue to stubbornly defend their rights until they obtain the definitive departure of the Moroccan aggressor from their territory and general recognition of the legitimacy of their struggle for self-determination and independence,” Sidati, the Foreign Minister of the self-declared Saharawi Arab Democratic Republic, said in a statement on Monday.

A high-ranking Moroccan official who spoke on the condition of anonymity called it “a game-changer” amid an international shift toward Morocco’s position. They noted France’s role as a permanent member of the United Nations Security Council, which oversees the peacekeeping mission that has for decades mediated between Morocco and the Algeria-backed Polisario Front.

Algeria said France had made it aware of the policy change in the days leading up to the announcement and called Morocco and France “colonial powers, new and old.”

“The French decision is clearly the result of a dubious political calculation, a morally questionable judgement and legal interpretations that are neither supported nor justified,” Algeria's Ministry of Foreign Affairs said in a statement last week.

Morocco annexed the Western Sahara, a former Spanish colony, in 1975, sparking a conflict with the pro-independence Polisario Front, which the United Nations has long recognized as the legitimate representative of the Saharawi people.

The U.N. brokered a 1991 cease-fire and established a peacekeeping mission to monitor the truce and help prepare a referendum on the territory’s future. Disagreements over who is eligible to vote prevented the referendum from taking place.

Morocco has long sought recognition of its claim from its other nations, while the Polisario has prioritized fighting legal battles to assert its right to represent the people and territory. Sporadic violence has ensued since the Polisario renewed armed conflict in 2020, ending a 29-year truce.

The longstanding territorial dispute is a major factor in many of North Africa’s foremost issues, including migration, smuggling and counterterrorism.