The mayor of Istanbul in Turkey has been arrested and one of Erdogan's biggest political opponents arrested

(Istanbul Bloomberg) - A Turkish court on Sunday formally arrested Istanbul mayor Emamoglu, President Recep Tayyip Erdogan's biggest political rival, on bribery charges. The move is expected to spark more protests.

Imamoglu, 54, is from Turkey's largest opposition Republican People's Party (CHP), which was due to announce him Sunday as its candidate for the 2028 presidential election.

However, Turkish police detained Imamoglu on Wednesday (19) on suspicion of leading a criminal organization, bribery, bidding manipulation and assisting a terrorist organization. The opposition denounced the move as politically motivated. Mr Imamoglu denies all the charges.

Since Imamoglu's detention, despite a ban on demonstrations issued by the authorities, large-scale protests have erupted for several days in major Turkish cities, including Istanbul, the capital Ankara, Izmir and other places. Tensions spilled over into financial markets over the past week, with Turkey's stock market plunging and an emergency interest rate hike failing to stop a sell-off in the Turkish lira.

Mr. Erdogan's aides have repeatedly touted his bid for a third term as president, which would extend more than two decades in power for Mr. Erdogan, who served as prime minister before becoming president. Imamoglu is favored to unseat Erdogan because he has defeated Erdogan's hand-picked candidates in two local elections.