Chileans go to the ballot box for the fourth time in 18 months as the country's economic woes have worsened with the coronavirus epidemic, unemployment and skyrocketing foreign debt.
Chilean voters have headed to the polls in what is widely seen as the nation's most divisive presidential election since the country's 1990 return to democracy.
Seven candidates will vie to replace the unpopular President Sebastian Pinera on Sunday, covering the entire political spectrum from left to right.
Polls open at 1100 GMT (8:00 AM local time), and close ten hours later. Results are expected late on Sunday. To win in the first round, a candidate must garner 50 percent of the votes cast.
However, given the abstention trend and high levels of voter indecision, analysts believe the election will likely go to a runoff round between the top two contenders on December 19.
With his second, non-consecutive term beset by economic and social upheaval, billionaire Pinera approaches the end of his mandate with record-low approval.
A large proportion of Chileans want a more interventionist and socially-minded government, better access to public health care and education and a change to the pension system, which is privately administered.
The favourites for Sunday’s elections are Gabriel Boric, 35, of the leftist Approve Dignity alliance which includes the Communist Party, and far right candidate Jose Antonio Kast, 55, of the Republican Party.
Both candidates have about a quarter of stated voter intention and are from minority parties not in government.
Centrists, including the candidate from Pinera's party, proved the least popular in opinion polls that also revealed half of the 15 million eligible voters to be undecided.
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The poll comes two years after a social revolt against deep-rooted inequality, and months after elections for a body that will draft the new constitution which is currently underway.
That ballot in May saw voters massively reject traditional political parties and elect a majority of mainly left-leaning independent candidates.
On Sunday’s ballot, Chileans will also replace the 155-member Chamber of Deputies and almost two-thirds of Senators.
This new-look Congress will be in place when the country decides in a mandatory referendum next year whether or not to adopt the new constitution.
It is not known how, or if, a changed constitution could impact on the terms or powers of the new president.