Tunisians are heading to the polls in a presidential election that will be a closely-fought contest between an old guard who flourished under decades of autocratic rule and a new breed of politicians that has emerged since a 2011 revolution, Al Jazeera reported.
Voting started at 7am local time (06:00 GMT) on Sunday and polling stations will close at 6pm. More than 4,500 polling booths have been set up to receive more than 5.2 million eligible voters.
The election has been billed as Tunisia's first free and fair poll since independence from France in 1956. The vote will also mark the first time one president hands over the reins to another.
The country has had just two presidents - the founder of modern Tunisia, Habib Bourguiba, and Zine El Abidine Ben Ali, who overthrew him in a bloodless coup in 1987. Moncef Marzouki has served as interim leader since Ben Ali was toppled in the uprising three years ago.
Secularist Beji Caid Essebsi, 87, is seen as the front-runner after his party Nidaa Tounes (Tunisian call) won last month's parliamentary polls, with Marzouki his main rival.
Transition to democracy
Some 27 candidates are competing in the race, the final brick in the construction of the country's nearly four years of transition.
The fact that there are 27 competitors may prevent a decisive victory with many analysts predicting that a vote of over 50 percent, required for an outright win, is unlikely to be achieved by any of the leading contenders.
At least 80,000 security personnel have been deployed around the country and up to 22,000 observers, 600 of them foreigners, are monitoring the elections.
In the event that no candidate secures an absolute majority, a second round of voting - pitting the two top candidates against each other - will take place on December 28.
Mohamed Salah Ben Aissa, professor of Public Law at the University of Legal, Political and Social Sciences of Tunis told Al Jazeera that all indications point to a run-off.
"It looks like Beji Caid Essebsi and Moncef Marzouki will respectively get the first and second spot in the first round of the presidential elections," Professor Ben Aissa said.
"There is also the possibility for Popular Front candidate Hamma Hammemi to move to the second round. It is a very slim possibility but he may occupy the second spot and that would be one of the surprises of this first round."
Old guard regroups
Front-runner Essebsi served as minister of the interior, defence and foreign affairs under the country's founding president, Habib Bourguiba.
He was then parliamentary speaker under deposed former leader Ben Ali, which has led to critics accusing him of seeking to restore the old regime.
"Essebsi enjoys wide electoral support, backed by leftists and unionists. He also enjoys the support of the country's long-established elites and those wanting a return to a more orderly era," Ben Aissa said.
Marzouki is relying on supporters of Islamist party Ennahda, which did not field a candidate of its own.
Other contenders to watch are Constituent Assembly head, Mustapha Ben Jaafar, and wealthy businessman and Club Africain football team chief, Slim Riahi, who leads the Free Patriotic Union party.
The elections are being held in a country that remains divided between secularists, who support Essebsi and Islamists who support Marzouki.
That Islamist-secular divide has also led to the emergence of a third sector of people in the country, who say they have experienced democracy fatigue and prefer not to get involved in the current political scene.
They argue that the political elites are either cronies of the old regime, too corrupt to be given another chance, or political newcomers who are too naive in politics and governance to be able to handle the challenges facing the country.
Results are expected early on Monday.