Thousands of supporters of jailed Turkish opposition politician Ekrem Imamoglu gathered on Istanbul's Sarachane Square on Wednesday to mark the one-year anniversary of his arrest and the start of nationwide protests.

Former Istanbul mayor Imamoglu, regarded as a potential challenger to Turkish President Recep Tayyip Erdogan, had his university degree revoked on March 18, 2025, before being arrested on terrorism and corruption charges a day later.

He was officially removed from the mayoralty on March 23 and has spent the last year in pre-trial detention in Istanbul's Silivri district.

Imamoglu's trial finally got underway earlier this month with prosecutors seeking to have him jailed for 2,430 years.

Turkey: Imamoglu slams 'corrupt mindset'

"The aim of this case is not to seek the truth or to ensure justice, but to escape the anxiety of electoral defeat," Imamoglu was quoted as saying in a message read out at the rally, which was organized by his Republican People's Party (CHP).

The message said the behind-closed-doors trial was "the product of a corrupt mindset that is mortally afraid of free and fair elections and has taken refuge behind the judiciary to eliminate its political rival."

Current CHP leader Ozgur Ozel, who also attended the demonstration, claimed that "hundreds of thousands" of Imamoglu's supporters were present — an exaggerated figure, but thousands of people did chant slogans such as "President Imamoglu!" and "Tayyip, resign!" while waving flags and banners amid a heavy police presence.

Since the CHP won a resounding victory in March 2024 in local elections against Erdogan's conservative, Islamic-rooted Justice and Development Party (AKP), it has faced a sweeping legal crackdown. Imamoglu is one of fifteen CHP mayors currently behind bars.

"Imamoglu was a presidential candidate and he was one step ahead," one 63-year-old female protester told the AFP news agency.

"He's been in jail for a year for no reason," she said. "Nothing holds up. It's all political."

Will Imamoglu be able to stand for election?

Analysts say Imamoglu almost certainly will not be able to contest the next presidential election, scheduled for May 2028 at the latest.

Even if he were cleared of graft charges, another lawsuit is challenging the validity of his university degree, a constitutional requirement for candidates in Turkey.

"I don't think there's any hope," a 39-year-old male protester told AFP. "He is Erdogan's biggest rival. They will hold him back and keep him isolated. [But] we'll use every opportunity we get. We chose him. We cannot just leave him in prison like this."

With Imamoglu likely to be barred, CHP leader Ozel is expected to emerge as the likely candidate for the presidential race.

"Who said we stayed silent? Who said we gave up and surrendered?" he asked the Istanbul rally, condemning the "civil coup that has been in place for 365 days" alongside Imamoglu's wife.

"Here are the ones who did not surrender, here are the ones who resist," Ozel said.

Edited by: Dmytro Hubenko