One embraces chaos and glorifies Turkey's Islamic past. The other promises the badly divided country a slightly calmer and more prosperous future.

The contrast between President Recep Tayyip Erdogan and his rival Kemal Kilicdaroglu could hardly be starker in Sunday's crucial election.

Erdogan is the man who rose from a hardscrabble part of Istanbul to become Turkey's longest-serving leader -- a devout 69-year-old who has created chronic headaches for the West and become a hero for Turkey's working classes.

"Erdogan is our chief and we are his soldiers," 48-year-old Sennur Henek told AFP while attending one of the president's packed campaign rallies.

Kilicdaroglu is a bookish former civil servant from a historically repressed Kurdish group who has lost half a dozen national elections to Erdogan while leading his secular party.

His frank kitchen chats with voters have turned him into a social media star at the age of 74.

Kilicdaroglu also promises to retire after stripping the presidency of Erdogan's powers and then "go spend time with my grandchildren".

Many say they are voting for Kilicdaroglu for the simple reason that he is not Erdogan.

"We have a party here that has been ruling for 20 years and that alone is a scandal," Ankara worker Mehmet Cankurnaz said on the eve of one of Turkey's most consequential elections of its modern era.

- 'Keeps his word' -

Erdogan's place in history already rivals that of Ottoman Sultans and Mustafa Kemal Ataturk -- the revered founded of secular Turkey.

He has overseen economic booms and busts while adhering to an Islamic vision of a great Turkey that is ready to go to war to defend its national interests.

Erdogan has launched offensives in Syria and jousted incessantly with Greece.

His interventions in Libya and Nagorno-Karabakh swung the outcomes of complex conflicts involving the interests of traditional great powers.

Erdogan's courtship of Russia upset Washington -- and his sale of weapons to Ukraine irritated the Kremlin.

But he seemed always to know how to play one off the other in order to come across as a statesman before his audience back home.

"This is a person who keeps his word -- a man," Russian President Vladimir Putin said of Erdogan in 2020.

"If he believes it is advantageous for his country, he goes to the end."

- 'I am not sinful' -

Kilicdaroglu hopes to swiftly undo what Erdogan spent more than two decades building.

He would start by moving the presidency out of the 1,100-room marble palace that Erdogan erected in Ankara and back into the more humble abode used by Ataturk.

"I will bring spring to this land. I will bring serenity," he once said.

It is a promise that has captivated the youth and a cross-section of Turks exhausted by Erdogan's culture wars and polarising rhetoric.

Kilicdaroglu also pledges to release many of the popular figures jailed by Erdogan's government in the wake of a failed but bloody 2016 coup attempt.

He vows to end Erdogan's "one-man regime" and the stigmatisation of feminists and the LGBTQ community.

But he is also trying to temper his secular stance by committing himself to prescribe Erdogan's removal of headscarf restrictions into Turkish law.

Kilicdaroglu's defining campaign moment came when he tweeted a video in which he broke a Turkish cultural taboo by talking about being Alevi.

The group has been targeted by violent repressions because it follows a more spiritual Islamic tradition that separates it from Sunni and Shiite Muslims.

"God gave me my life," Kilicdaroglu said in the video. "I am not sinful."

- 'Devil you know' -

Some analysts are portraying the vote in terms as stark as the difference between the two candidates.

"Either Erdogan will lose, giving Turkey a chance of restoring full democracy, or he will win and likely remain in power for the rest of his life," Washington Institute senior fellow Soner Cagaptay said.

Others highlight the economic relief that would come were Kilicdaroglu given a chance to tackle Turkey's dire cost-of-living crisis with orthodox financial prescriptions.

"Policy differences over the economy are the reason why markets will be watching this election closely," said Hamish Kinnear of the Verisk Maplecroft consultancy.

But veteran Turkey watcher Timothy Ash posed a contrarian question.

"Will voters opt for the 'devil you know' in Erdogan or an untested broad coalition which could easily splinter after elections?" Ash asked.

"And with Erdogan, they know he will strut his stuff on the international stage, batting for what he, and many of them, will view as Turkish national interests."

Ash still predicted a narrow Kilicdaroglu win.

zak/giv/lb