The poll is the second in just five months, called after President Recep Tayyip Erdogan’s Justice and Development Party (AKP) was stripped of its parliamentary majority in June for the first time in 13 years and then failed to forge a coalition government.
Opinion polls are predicting a replay Sunday, leaving the strategic Muslim-majority nation of 78 million at risk of further instability just as it faces what some warn are existential threats.
Around 385,000 police and gendarmes have been mobilised nationwide, with security particularly high in the restive Kurdish majority southeast, where armoured vehicles and police were seen outside polling stations.
The political landscape has changed dramatically in Turkey since June and the country is even more polarised on ethnic and sectarian lines.
‘All I want is peace’
Turks are fearful of a return to all-out war with outlawed Kurdistan Workers’ Party (PKK) rebels after fresh violence shattered a 2013 truce in July, just a month after a pro-Kurdish party won seats in parliament for the first time, denying the AKP a majority.
The threat of further jihadist violence is also overshadowing the poll after a string of attacks blamed on the Islamic State group, including twin suicide bombings on an Ankara peace rally last month that killed 102 people — the worst in Turkey’s modern history.
“All I want is peace and brotherhood, we have suffered too much lately,” 43-year-old Kiziltoprak Mahmut told AFP in the main Kurdish city of Diyarbakir.
Turnout is expected to be high among the 54 million registered voters and there were early queues at polling stations.
Erdogan’s conservative, Islamic-leaning AKP is tipped to take between 40 and 43 percent, paving the way either for a shaky coalition with one of the three other partiles likely to win seats, or yet another election.
“We are calling on our people to demonstrate their will and turn this day into a democracy feast… no matter what the outcome,” said Prime Minister Ahmet Davutoglu, whose own job could be at risk if the AKP fails to secure an outright victory.
The vote could also determine the future of Erdogan, the divisive figure who has dominated Turkey’s political scene for more than a decade.
The June result wrecked — at least temporarily — his ambition to expand his role into a powerful US-style executive presidency that opponents fear would mean fewer checks and balances on a man seen as increasingly autocratic.
A string of high-profile raids against media groups deemed hostile to Erdogan and the jailing of critical journalists have set alarm bells ringing about the state of democracy in a country that has long aspired to join the European Union.
“The AKP has turned this country into a wasteland,” said 55-year-old engineer Selim Ciftci as he voted in an Ankara district. “It’s enough!”
Security remains the paramount concern after the Ankara attack, blamed on an Islamic State sleeper cell, and police rounded up scores of IS suspects in nationwide raids last week.
Increasingly isolated on the world stage, Turkey is also struggling with its policy on Syria and the burden of more than two million people who have taken refuge from its neighbour’s bloody four-and-a-half year civil war.
After long supporting rebels fighting the Damascus regime, Ankara was cajoled into joining the US-led coalition against the IS group and launched its own “war on terrorism” targeting the jihadists as well as PKK fighters.
Further political turmoil could also add to jitters about Turkey’s economy, with growth slowing sharply from the dizzy heights of five years ago and the Turkish lira plunging more than 25 percent this year.
All eyes will again be on the Peoples’ Democratic Party (HDP), which made history in June when it became the first pro-Kurdish movement in parliament and gained enough seats to block an AKP majority.
But it faces accusations it is a front for the PKK, whose armed campaign for autonomy has killed 45,000 people since 1984.
“I hope the outcome of today’s election will raise hopes for peace. This is what Turkey needs the most right now. It’s in our people’s power to change our future, to have a stronger democracy,” said charismatic HDP leader Selahattin Demirtas after he voted.
Analysts expect the AKP to try to form a coalition with at least one other party in the event of another hung parliament, probably the main opposition CHP.
The Nationalist Movement Party (MHP), which shares a similar voter base to the AKP, has however ruled out joining any coalition with the HDP.
An inconclusive outcome could be an embarrassment for Turkey as it hosts world leaders, including US President Barack Obama, for a G20 summit on November 15-16.