Prime Minister Tayyip Erdogan said Sunday's bitterly contested local elections would affirm his legitimacy in battling graft allegations and security leaks he blames on "traitors" within the Turkish state.
The municipal elections have become a crisis referendum on Erdogan and his Islamist-rooted AK Party after weeks of scandal he has cast as a "dirty campaign" of espionage to implicate him in corruption and topple him after more than a decade in power.
Early results broadcast on Turkish television, with less than a fifth of votes counted, put the AKP ahead with between 44 and 48 percent of the vote. AKP needs to exceed its 2009 result of 38.8 percent to assert Erdogan's authority for a power struggle certain to continue after the polls.
Istanbul and Ankara, the two biggest cities, are expected to be particularly close. Two buses of riot police stood ready in Istanbul's plush Nisantasi neighborhood, one of several districts rocked by anti-government protests last summer.
"Once the ballot boxes are opened, the rest is only footnotes to history," Erdogan said as he voted in Istanbul.
"Today it is what the people say which matters rather than what was said in the city squares," he told reporters, as supporters chanted "Turkey is proud of you" outside.