Istanbul, Jun 23 : Istanbul went back to the polls on Sunday in a re-run of the mayoral election that has become a test of Turkish democracy as well as President Recep Tayyip Erdogan's continued popularity at a time of economic trouble.
Election authorities annulled the first vote in March after Erdogan's party alleged corruption in a count that showed the ruling AKP's candidate had narrowly lost.
Polling stations opened at 0500 GMT and the 10.5 million registered voters have until they close at 1400 GMT to elect the new mayor.
Critics say Erdogan simply did not like the March 31 result, after a little-known former district mayor, 49-year-old Ekrem Imamoglu, snatched victory for the opposition by just 13,000 votes.
The city of 15 million is Turkey's economic powerhouse and has been a crucial source of patronage for Islamic conservatives since Erdogan himself won the mayorship a quarter-century ago.
But Imamoglu, of the secular Republican People's Party, has become a household name since being stripped of his victory.
He has vowed a "battle for democracy" and used an upbeat message under the slogan "Everything will be fine", in stark contrast to the usual aggressive name-calling of Turkish politics.
He will again face Binali Yildirim, a mild-mannered Erdogan loyalist who oversaw several huge transport projects and served as prime minister.
Fearing fraud, the opposition has mobilised an army of lawyers from across Turkey to monitor Sunday's election, with the Istanbul Bar Association unfurling a huge banner at their headquarters that reads: "Stand guard for democracy".
The March election showed Erdogan's party remains the most popular in Turkey, adored by millions for overseeing dramatic growth, fiercely defending the country's interests abroad and allowing religious conservatives a seat at the table.
But double-digit inflation and rising unemployment have dented Erdogan's reputation for economic stewardship.
Analysts warn he faces a "lose-lose" situation on Sunday: an embarrassing second defeat, or a victory that the opposition will claim was stolen out of their hands.
The re-run has also infuriated voters by forcing them back to the polls for the eighth time in just five years.
The controversy may explain Erdogan's relative silence, with no repeat of the tireless rallying last time, when he made 102 appearances in just 50 days.
Last weekend, he dismissed the Istanbul vote as "only a change in the shop window" since the AKP already runs almost two-thirds of the city's districts.
The AKP has still gone to great lengths, calling on conservative voters who abstained in March.
It has also tried to win over Kurds, who number in the millions in Istanbul and have been angered by the suppression of Kurdish rights in recent years.
Yildirim travelled to one of the main Kurdish cities of Diyarbakir this month and uttered the word "Kurdistan" -- a taboo in Turkey.
There have even been signs of dialogue with the jailed leader of the Kurdish insurgency, Abdullah Ocalan, who has spent 20 years in near-total isolation on a prison island.
Ocalan was able to issue a statement this week, calling on the pro-Kurdish Peoples' Democratic Party to remain neutral in the Istanbul election, though they continue to back the opposition.
Analysts say Erdogan, who has won every election since 2002, should never be counted out.
But a second loss in Istanbul would undermine his image of invincibility and possibly embolden rivals such as ex-prime minister Ahmet Davutoglu, who is said to have toyed with founding a new party. [Agencies]
