A new opinion poll shows jailed İstanbul Mayor Ekrem İmamoğlu leading President Recep Tayyip Erdoğan by about 16 percentage points in a hypothetical presidential runoff election, the Cumhuriyet daily reported.
According to the survey conducted by Gündemar Research, respondents were asked whom they would support if a second-round presidential election were held this Sunday between Erdoğan and İmamoğlu. The results showed İmamoğlu with 58.13 percent of the vote, compared with Erdoğan’s 41.87 percent.
İmamoğlu, a senior figure in the main opposition Republican People’s Party (CHP), is being held at Marmara Prison in Silivri pending trial on corruption-related charges. His supporters say the case is politically motivated, a claim the government denies.
Gündemar’s “Turkey Agenda” survey was conducted between December 20 and 26, with 2,365 respondents from 60 provinces across Turkey. The study used a combination of computer-assisted telephone interviews and computer-assisted web interviews.
The poll also tested an alternative opposition scenario involving Ankara Mayor Mansur Yavaş, who is also from the CHP and is seen one of the potential challengers of President Erdoğan in the next general election. In that matchup Yavaş led Erdoğan by a wider margin, winning 63.17 percent of the vote against Erdoğan’s 36.83 percent.
The CHP declared İmamoğlu as its presidential candidate following a March 23 primary held the day of his arrest, but the party is also considering alternatives if he is barred from the race.
In the same survey’s parliamentary voting question, the CHP remained the leading party with 34.30 percent support after undecided voters were distributed. Erdoğan’s ruling Justice and Development Party (AKP) followed with 29.72 percent, leaving a gap of about five points between the two.
Compared with Gündemar’s previous poll, the CHP lost 1.61 percentage points, while the AKP gained 1.22 points.
Gündemar Research Chairman Prof. Dr. Tamer Bolat said surveys conducted since June 2025 showed no sharp fluctuations between the ruling and opposition blocs, pointing to what he described as a new political equilibrium.
He said the government continues to rely on a stable core electorate but has struggled to expand its support.
Bolat said the CHP’s advantage appeared to stem more from voter fatigue and dissatisfaction with the government than from strong social mobilization, adding that undecided and other voters who cast their ballots for another party in protest continue to represent a significant bloc in Turkish politics.
One of the survey’s notable findings was a sharp decline in support for the far-right Nationalist Movement Party (MHP), the AKP’s ally, which fell to 4.38 percent, a drop of 0.66 points from the previous poll.
The results also showed changes in levels of support among smaller right-wing parties.
Turkey is scheduled to hold the next general election in 2028.
The survey’s findings come against the backdrop of a wide-ranging government crackdown targeting the CHP since October 2024, when the party won İstanbul, Ankara and other major cities and secured the largest share of the national vote for the first time in decades.
A recent CHP report documented mass detentions, politically motivated investigations and the appointment of government trustees to CHP-run municipalities. According to the report, 16 CHP mayors remain behind bars, and trustees have been imposed on 13 municipalities, including İstanbul’s Esenyurt and Şişli districts.
The crackdown escalated sharply after the arrest of İmamoğlu.
The CHP report describes the multiple legal cases against İmamoğlu, including his prison sentences for allegedly insulting election officials and a prosecutor, as “the most visible examples of political pressure on the opposition.”