Turks voted on Sunday in municipal elections with all eyes on Istanbul, the national "jewel" that President Recep Tayyip Erdogan has aimed to pry away from the opposition.

The last polling stations closed at 1400 GMT in the west of the country and the first estimates were expected to be released late on Sunday.

The election took place against the backdrop of raging inflation and massive devaluation, with the uncertainty weighing down on many voters, AFP correspondents reported.

"Everyone is worried about the day to day" 43-year-old Guler Kaya said at an Istanbul station.

"When Turkish people vote, the situation in the kitchen or on their plate changes the voting trend," Ali Faik Demir, a political scientist at Galatasaray University, told AFP.

Vote change happens "when we cannot afford a living, when we cannot eat", he said.

Erdogan may not have been a candidate in the municipal vote, but he dominated the campaign.

His road to power in Turkey began in Istanbul when he was elected mayor of the mythic city straddling Europe and Asia in 1994.

His allies held the city until five years ago, when Ekrem Imamoglu of the secular Republican People's Party (CHP) wrested control.

If Imamoglu retains his seat, he will likely be the main opponent to Erdogan's ruling AKP party in the next presidential elections in 2028.

As soon as Erdogan clinched re-election as president last May - he has held the position since 2014 - he launched the battle to reclaim the city of 16 million people.

"Istanbul is the jewel, the treasure and the apple of our country's eye," the 70-year-old leader said at a recent rally in the city. (AFP)