Ivory Coast Vice President Daniel Kablan Duncan has resigned, the presidency, further unsettling the political outlook days after the sudden death of prime minister Amadou Gon Coulibaly, President Alassane Ouattara’s preferred successor.

The death last week of Gon Coulibaly, hand-picked by Ouattara to run in October’s presidential election, has left the ruling party scrambling to find a replacement candidate, a process likely to reveal internal divisions, analysts say.

Duncan is leaving for “reasons of personal convenience”, Patrick Achi, a top aide to Ouattara, told reporters, adding that Duncan had first tendered his resignation in February.

He said Ouattara had finally accepted Duncan’s resignation last Wednesday, the same day Gon Coulibaly, who had longstanding heart problems, died after a cabinet meeting.

Despite several years of relative peace, ethnic and regional rivalries linger, and this year’s election is seen as test of stability for Ivory Coast, the world’s top cocoa producer and one of West Africa’s largest economies.