The two leading candidates have presented dramatically different visions for both Colombia's economic model and the future of its divisive peace process.
BOGOTA, Colombia — Colombians vote on Sunday in a deeply divisive presidential ballot that has stirred fears the winner could upset a fragile peace accord with Marxist rebels or derail the nation's business-friendly economic model.
In the first election since the peace deal was signed in 2016 with the Revolutionary Armed Forces of Colombia (FARC), voters will decide on a replacement for President Juan Manuel Santos, who won the Nobel Peace Prize for ending the five-decade-old conflict.
Leading candidate, right-wing Ivan Duque, has pledged to alter the terms of the peace deal and to jail former rebels for war crimes. Leftist Gustavo Petro, polling second, has said he would overhaul Colombia's orthodox economic policy and redistribute wealth from the rich to the poor.
Trailing them in the often-unreliable polls are mathematician and centrist Sergio Fajardo and former vice president German Vargas, who has Santos' support.
If no candidate gets more than 50 percent, the top two will go to a runoff on June 17.
Campaigning in the traditionally conservative nation has been marked by acrimonious accusations that rival candidates will collapse the economy with socialist policies, force the nation back to the battle field or bust the budget by overspending.
"These elections will decide the future of Colombia and maybe steer it toward an even more divided society that could end in a deep crisis," said Gregorio Sierra, a 52-year-old psychologist in the capital, Bogota. "It's scary."
Business-friendly Duque, who was handpicked by hard-line former President Alvaro Uribe, has promised to cut corporate taxes and support oil and mining projects, as well as change the peace accord and impose tougher punishments for former FARC fighters.
Under the terms of the deal, thousands of rebels demobilized and the group is now a political party. But the accord drew ire from many who believe the FARC should be in prison and not in Congress.
Some areas abandoned by the FARC have suffered an increase in fighting between criminal gangs and remaining guerrilla group the National Liberation Army (ELN) over valuable illegal mining and drug trafficking territories. Colombia's production of coca - the raw material for cocaine - has risen sharply, stirring concern in Washington.
The election also coincides with a growing migration crisis from neighboring Venezuela. Colombia is appealing for international support to cope with hundreds of thousands of Venezuelans streaming across the border to flee shortages of food and rising crime as their nation's economy implodes.