ISTANBUL — As Turkish President Recep Tayyip Erdogan hosted NATO leaders in Ankara on Wednesday, his main political rival defended himself against corruption charges in court.

Istanbul Mayor Ekrem Imamoglu, who represents the Republican People’s Party, or CHP, was arrested in March 2025. Hundreds of party members and elected officials have been detained over the past two years in a crackdown critics say is designed to cripple Turkey’s largest opposition group.

In a specially built court next to the Silivri prison complex outside Istanbul, Imamoglu protested the judge’s barring him from attending hearings for almost a week over “disruptive behavior,” saying his legal rights had been disregarded.

“How can you explain to world leaders at the NATO summit, in Turkey, in Ankara, the silencing of Ekrem Imamoglu?” he asked the presiding judge, according to the opposition-backing Cumhuriyet newspaper.

The CHP selected Imamoglu as the party’s future presidential candidate shortly after his arrest, and he is widely seen as the main challenger to Erdogan’s 23-year rule. In May, the CHP’s leadership was removed by a court order that annulled its 2023 congress.

The government maintains that Turkey’s judicial system is independent and free of political interference.

Wednesday’s hearing was for the largest case Imamoglu faces. It alleges he led a criminal organization as the head of the Istanbul Metropolitan Municipality that was involved in widespread corruption. He faces 142 charges, including establishing what the prosecution called the “Imamoglu criminal organization for profit” from 2015, when he was mayor of Istanbul’s Beylikduzu district.

The 3,900-page indictment alleges the goal was not only to financially benefit Imamoglu and some of his 413 co-defendants through a system of bid rigging and payoffs, but also to finance his rise within the CHP, ultimately culminating in his presidential candidacy.

Speaking about the corruption charges against him on Wednesday, Imamoglu said, “not a single piece of evidence or document … Not a single audio recording could be presented” to prove the prosecution’s case.

If convicted, he could face a total prison sentence exceeding 2,000 years.

The court has declared that submissions will finish on Thursday, giving Imamoglu just one day to present his defense.

Meanwhile, the Bakirkoy Prosector’s Office in Istanbul announced a fresh criminal investigation into Imamoglu for “threatening a public official” during his courtroom comments Wednesday, citing remarks that he would “judge those who prepared the indictment” against him.

On Monday, the 62nd hearing in the corruption case was held at the same time as hearings in two other separate cases against Imamoglu: one alleging that he fraudulently obtained his bachelor’s degree in 1994 and the other claiming that he committed political and military espionage.

The European Parliament rapporteur for Turkey, Nacho Sanchez Amor, pointed to the timing in the run-up to the NATO conference.

“These hearings are happening today because there’s a NATO summit in Ankara,” he told reporters outside the courthouse on Monday. “It’s statistically impossible that there can be three hearings for the same person for three cases on – a great surprise – the same day that attention is on Ankara with another summit.”

Imamoglu came to prominence when he won Istanbul for the CHP in 2019, taking Turkey’s largest city from Erdogan’s Justice and Development Party, or AKP, and its predecessors for the first time in 25 years.

The mayor retained his seat in the 2024 local elections, during which the CHP made further significant gains against the AKP.

Turkey’s next presidential and parliamentary elections are due in 2028, but the government may call for earlier polls.