By Jonny Hogg
ANKARA (Reuters) - Turks go to the polls on Sunday amid worsening security and economic worries, in a snap parliamentary election that could profoundly impact the divided country's trajectory and that of President Tayyip Erdogan.
This is the second parliamentary poll in five months, after the ruling AK Party founded by Erdogan failed to retain its single-party majority in June. Since then, a ceasefire with Kurdish militants has collapsed into bloodshed, the Syria crisis has worsened, and NATO-member Turkey has been hit by two Islamic State-linked suicide bomb attacks, killing more than 130.
There has been little sign of the flags, posters and campaign buses that thronged the streets in the build-up to June's vote, but Erdogan has framed this somber re-run as a pivotal opportunity for Turkey to return to single-party AKP rule after months of political uncertainty.
"This election will be for continuity of stability and trust," he said after praying at a new Istanbul mosque on Saturday. He vowed to respect the result.
Erdogan's critics say the vote, prompted by the AKP's inability to find a junior coalition partner after the June result, represents a gamble by the combative leader to win back enough support for the party so it can eventually change the constitution and give him greater presidential powers.
Many polls suggest that while support for the center-right, Islamist-rooted party may have inched up, the outcome is unlikely to be dramatically different to June, when it took 40.9 percent of the vote.
However, one survey released on Thursday suggested there had been a late surge in support for the AKP and that it could take as much as 47.2 percent, comfortably enough to secure more than half of the 550-seat parliament.
Whatever the outcome, deep polarization in Turkey - between pious conservatives who champion Erdogan as a hero of the working class, and Western-facing secularists suspicious of his authoritarianism and Islamist ideals - is likely to remain.
"The political uncertainty, growing social divisions and insecurity which has characterized the period between the two elections seems set to continue," Bulent Aliriza, director of the Turkey Project at the Washington-based think-tank CSIS, said in a note on Friday.
If the AKP fails again to secure a single-party majority, it may be forced back to the negotiating table with either the country's main secularist CHP opposition or the nationalist MHP.
Some Western allies, foreign investors and Turks see a coalition with the CHP as the best hope of easing sharp divisions in the NATO member and EU candidate nation, and say it could keep Erdogan's authoritarian instincts in check.
Raids in recent days on opposition media linked to Erdogan's arch enemy, U.S.-based cleric Fethullah Gulen, including the closure of two TV stations and seizure of newspapers, have heightened fears about the erosion of freedom of speech and the rule of law.
"This is an important election ... I expect an AKP-CHP coalition. It could help maintain stability," said Veysel, a 21-year-old apprentice barber in the capital, Ankara.
AKP officials are hoping the uncertainty and insecurity of recent months will steer voters who remember the fragile coalition governments of the 1990s back to the AKP, and are betting a recent crackdown on the outlawed Kurdistan Workers' Party (PKK) will claw back nationalist votes.
Investors and Turkey's Western allies hope the vote will usher in stability and shore up confidence in the economy, allowing Ankara to play a more central role in stemming Europe's migrant crisis and helping in the fight against Islamic State. Turkey jets launched bombing raids against Islamic State targets in Syria on Saturday ahead of the election.
(Additional reporting by Can Barut in Ankara, Melih Aslan in Istanbul; Editing by David Dolan, Nick Tattersall and Digby Lidstone)