معركة أنوال
He did not return until April 1918, when he had been elected to the Spanish Congress of Deputies. Very critical of the actions of the government and army during the Rif War, or "War of Melilla" (1919–1926), Prieto spoke out strongly in the Congress after the Battle of Annual (1921). He also addressed the likely responsibility of the king in the imprudent military actions of General Manuel Fernández Silvestre in the Melilla command zone.