President Recep Tayyip Erdogan's job approval stood at 44.5% across Türkiye, while 51% of respondents said they disapproved of his performance, according to a new Metropoll Research survey.
The remaining 4.5% of respondents did not express an opinion.
The results varied significantly according to respondents' voting preferences in the May 2023 parliamentary election.
Among voters of the ruling Justice and Development Party (AK Party), 81.1% approved of Erdogan's performance, while 16.2% disapproved.
Approval stood at 60% among voters of the Nationalist Movement Party (MHP), the AK Party's main ally, while 40% said they disapproved.
Disapproval was higher among opposition voters. Some 83.4% of Republican People's Party (CHP) voters and 88.8% of Good Party (IYI Party) voters said they disapproved of Erdogan's performance.
The CHP continues to grapple with a leadership dispute triggered by a court decision invalidating the party's 2023 congress over alleged procedural irregularities and ordering a new leadership vote.
An Ankara court in May annulled the CHP's 2023 leadership election over allegations of vote buying and reinstated former Chairperson Kemal Kilicdaroglu as interim leader.
The ruling temporarily restored the party's pre-congress administration under Kilicdaroglu to oversee preparations for a fresh congress.
CHP officials have denied allegations that the original leadership contest was tainted by misconduct.
Metropoll surveyed through computer-assisted telephone interviews with 1,165 people in 28 provinces between June 15 and June 25.