Key Turkish opposition figure set to run again for Istanbul mayor

"As I have said many times: who wins in Istanbul also wins in Turkey. Success in Istanbul would take one to very important spots in national politics," Imamoglu, who runs the country's largest city, told reporters.

Imamoglu was not picked as the opposition leader in May national elections but is seen as one of its best hopes to unseat President Tayyip Erdogan in the years ahead. He has called for a "total change" in the opposition since Erdogan defeated its candidate, Kemal Kilicdaroglu, on May 28.

Kilicdaroglu has remained chairman of the main opposition Republican People's Party (CHP) despite growing calls to resign, and has not said whether he will stand as a candidate in the party congress this autumn.

Some analysts see Imamoglu as a possible successor.

"Today I'm setting out to defend Istanbul again, I'm setting out for the grand Istanbul alliance again," Imamoglu said.

CHP cooperated with the center-nationalist IYI Party and pro-Kurdish HDP in 2019 municipal elections to secure Imamoglu's victory in Istanbul, which came as a shock to Erdogan and his ruling AK Party.

The two parties have not revealed whether they will support the CHP candidate again in the March 2024 vote.