Turkish authorities on Wednesday detained Istanbul Mayor Ekrem Imamoglu, a prominent figure in the main opposition Republican People’s Party (CHP), on charges including graft, leading a criminal organization, and aiding a terrorist group. The move has been slammed by the CHP as a “coup attempt against the next president,” raising the political stakes ahead of the next election.

Imamoglu, long viewed as President Tayyip Erdogan’s most formidable rival, rose to national prominence in 2019 by orchestrating a surprise victory in Istanbul’s mayoral race, twice defeating the ruling AK Party’s candidate after a controversial election rerun. His subsequent re-election in 2024 only solidified his position as a viable contender to Erdogan, should he stand again.

In a video message posted on X, Imamoglu vowed, “I will not give up,” urging supporters to see the charges as politically motivated. Erdogan’s government denies allegations that it is using the courts to sideline political opponents, even as Imamoglu faces additional legal hurdles—including the recent annulment of his university degree that could jeopardize his eligibility to run for president.

The Istanbul prosecutor’s office alleges Imamoglu was involved in bribery, tender rigging, and assisting the outlawed Kurdistan Workers’ Party (PKK). Imamoglu’s supporters, however, recall parallels to Erdogan’s own political ascent, which also included legal setbacks and a tenure as Istanbul mayor. The CHP warns that the detention—together with a newly imposed four-day protest ban in Istanbul—undermines Turkey’s democratic institutions and casts doubt on the fairness of future elections.