Chileans were voting for a new president on Sunday following a polarising campaign in which the leading candidates vowed to chart starkly different paths for the region’s most economically advanced country hit by a recent wave of social unrest.

Pre-election polls point to a large number of undecided voters but have consistently favoured two of the seven candidates running: former student protest leader Gabriel Boric and his ideological opposite, Jose Antonio Kast, who has a history of defending Chile’s past military dictatorship.

But neither is expected to garner enough support to cross the 50% threshold required to avoid a runoff vote next month.

Within striking distance of the two frontrunners are centre-right candidate Sebastian Sichel and centre-left former education minister Yasna Provoste.

Also up for grabs is Chile’s entire 155-seat lower house of Congress and about half of the Senate.

Mr Boric, 35, would become Chile’s youngest modern president. He was among several student activists elected to Congress in 2014 after leading protests for higher quality education.

Running as the head of a broad alliance that includes Chile’s Communist Party, he says that if he is elected he will raise taxes on the “super rich” to expand social services and boost environmental protections.

He has also vowed to eliminate the country’s private pension system — one of the hallmarks of the free market reforms imposed in the 1980s by General Augusto Pinochet’s dictatorship.

Mr Kast, 55, from the newly formed Republican Party, was seen as an outsider on the far-right fringe until recently, having won less than 8% of the vote in 2017 as an independent.

But he has been steadily rising in the polls this time with a divisive narrative emphasising conservative family values as well as attacking migrants – many from Haiti and Venezuela – who he blames for crime.

A fervent Roman Catholic and father-of-nine, Mr Kast has also taken aim at the outgoing president Sebastian Pinera for allegedly betraying the economic legacy of Pinochet, which his brother helped implement as the dictator’s central bank president.

Whoever wins will take over a country in the grip of major change but uncertain of its future course after decades of centrist reforms that largely left Pinochet’s economic model untouched.

Mr Pinera’s decision to raise underground railway fares in 2019 sparked months of massive protests that quickly spiralled into a nationwide clamour for more accessible public services and exposed the crumbling foundations of Chile’s “economic miracle”.

Gravely weakened by the unrest, Mr Pinera begrudgingly agreed to a referendum on rewriting the Pinochet-era constitution. In May, the assembly charged with drafting the new document was elected and is expected to conclude its work sometime next year.

Meanwhile, in a fresh sign of the tensions Mr Pinera will leave behind, the billionaire president was impeached in the lower house before dodging removal by the Senate over an offshore business deal in which his family a decade ago sold its stake in a mining project while he was serving the first of two non-consecutive terms.