ISTANBUL, March 19: Istanbul's powerful mayor Ekrem Imamoglu is President Recep Tayyip Erdogan's biggest political rival who has faced a growing barrage of legal challenges aimed at stopping his bid to win Turkey's top job.
After a sensational entry into politics in 2019 when he was elected mayor of Turkey's economic powerhouse, Imamoglu quickly became a key figure within the main opposition Republican People's Party (CHP).
But his career has been overshadowed by a string of what critics say are politically-motivated legal cases designed to cripple his plans to contest Turkey's 2028 presidential election.
In the latest blow, police raided his house early Wednesday, detaining him on alleged corruption charges in a move swiftly denounced by the CHP leader Ozgur Ozel as "a coup attempt against our next president".
Media reports also spoke of a second probe into allegedly aiding the banned Kurdistan Workers' Party (PKK).
The move came a day after Istanbul University revoked his degree -- a high-stakes move as Turkish presidential candidates must have a higher education diploma.
Berk Esen, a political scientist at Istanbul's Sabanci University, said Imamoglu's detention was "nothing short of a coup against the main opposition party, with far-reaching consequences for Turkey's political trajectory."
Widely seen as best placed to challenge Erdogan in 2023, Imamoglu didn't run after being hamstrung by an unresolved defamation conviction.
Since then, his legal woes have multiplied with three new probes targeting him this year alone. He decried them as "the highest level of judicial harassment".
His re-election as mayor last year despite Erdogan's best efforts to unseat him has cemented the popularity of the football-loving 53-year-old, who had been due to be formally named as CHP's presidential candidate on Sunday.
Born in Akcaabat, a seaside town on Turkey's Black Sea coast, Imamoglu moved to Istanbul as a teenager.
He studied business, then went to work in the construction industry.
He was a political unknown until he managed to oust Erdogan's AKP and its allies in 2019 from their 25-year dominance of the city of 16 million where the president was once himself mayor.
As Erdogan's own career path has shown, running the megalopolis is a tried-and-tested route to national power.
Initially stripped of victory when the vote was annulled, he won by an even bigger margin in a re-run three months later.
"You have opened the door to a new future. From now, Turkey will be a different country," he told his ecstatic followers at the time.
His emergence in 2019 came as a wave of anti-Erdogan sentiment ushered in a fresh generation of leaders from the staunchly secular CHP, including a new mayor of the capital Ankara.
In 2022, Imamoglu was convicted of defamation for calling Istanbul election officials "idiots" and sentenced to two years and seven months in jail.
He appealed, but the outcome remains pending, with the ever-present jail threat prompting the CHP not to field him as a candidate for the 2023 presidential poll.
Another investigation opened in 2023 named him in another corruption case allegedly linked to rigging tenders while mayor of Beylikduzu, an Istanbul district.
In November, Erdogan sued Imamoglu for slander, raising the prospect he could be prosecuted for insulting the president -- an offence carrying up to four years in jail which has been widely used to silence rivals, journalists, human rights defenders and members of the public.
In January, prosecutors opened two new probes over his remarks about Istanbul's chief prosecutor and a court-appointed expert used in cases against CHP-run municipalities.
"Imamoglu is an effective political operator... (who) represents one of the very few glimmers of hope for constituents who oppose Erdogan and the AKP," said Anthony Skinner, director of research at geopolitical advisory firm Marlow Global.
A practising Muslim in a secular party, the smooth-talking politician has won support from a wide spectrum of voters.
"He can attract all segments of the opposition electorate, whether it's Turkish or Kurdish, Sunni or Alevi, young or old," said political scientist Esen.
And he has trodden a careful line on sensitive issues, such as same-sex marriage which is illegal in Turkey.
"I'm a person who respects freedoms... But our society is not yet ready to allow same-sex marriage," he said in a 2020 TV interview.
"Imamoglu communicates well with the public -- he gives sincere answers and can easily connect with people," Sukru Kucuksahin, who worked with him on the 2019 election campaign, told AFP.
But like Erdogan, Imamoglu also has something of a "Black Sea temperament", he said, referring to people known for being blunt and often very stubborn.
Imamoglu has not been embraced by all of the opposition, with some saying he's a careerist.