Colombians go to the polls on Sunday in a presidential runoff expected to trigger to a dramatic shift in the country’s decades-long armed conflict, now at its most violent point since the landmark 2016 peace agreement between the government and most of the Revolutionary Armed Forces of Colombia (Farc).

Polls show the frontrunner is the Trump-admiring far-right lawyer and millionaire businessman Abelardo de la Espriella, who has vowed to abandon President Gustavo Petro’s “total peace” plan of negotiating the disarmament of all criminal organisations and instead return to full-scale military confrontation with armed groups.

De la Espriella’s opponent in the ballot will be Petro’s chosen successor and the main architect of “total peace”, the leftwing senator Iván Cepeda, who argues for the continuation of the plan, with “necessary changes”.

Cepeda led the polls throughout most of the campaign but was defeated in the first round three weeks ago and has since struggled to attract centrist voters.

The election, in which more than 41 million Colombians are eligible to vote, is expected to deliver another victory for a far-right candidate advocating an iron-fist approach to crime, after the examples of Keiko Fujimori, who is leading the vote count in Peru, and José Antonio Kast, who won last year’s election in Chile.

Amid what many analysts see as a new wave of far-right victories across Latin America, a De la Espriella presidency would leave only Mexico, Brazil, Uruguay and Guatemala under leftwing governments.

Sandra Borda Guzmán, an associate professor of political science at Los Andes University in Bogotá, said De la Espriella successfully tapped into two trends that have shaped recent elections around the world: presenting himself as an anti-establishment “outsider” and promising quick solutions to violence.

He even promised that, if elected, he would restore state control over territories dominated by criminal groups within 90 days – although he later appeared to backtrack, telling Radio Caracol: “I never said I would solve the security problem in 90 days.”

De la Espriella, a lawyer who launched his legal career defending leaders of rightwing paramilitary militias, maintained that his goal during his first three months in office would be to “capture or kill” 10 major narcoterrorist and organised crime leaders.

“Between the international trend favouring candidates who present themselves as anti-political figures and Colombia’s domestic security situation, that combination has helped him significantly,” said Guzmán.

Although violence remains far below the extraordinarily high levels recorded in the decades before the peace deal with the Farc, the past year has been the most violent since the 2016 agreement.

Miguel Bermúdez, a 40-year-old business administrator from the coastal city of Cartagena, said he would vote for De la Espriella largely because he is an “outsider” despite his long history as a lawyer for the rich and powerful.

“For a long time, I’ve been looking for something that feels fresh. I’m tired of that same old political narrative,” said Bermúdez.

Kátia Outten, a 57-year-old dentist from the island of San Andrés, said she would vote for Cepeda because “he understands the needs of ordinary people”.

During his presidency, Cepeda’s backer Petro expanded social programmes and increased the minimum wage. The poverty rate has fallen to its lowest level since records began in 2012.

Outten also decided not to vote for De la Espriella because of what she sees as his sexist views, including a radio interview in which he claimed to have won support among female voters because of the size of his penis.

“Women make up just over 50% of the population. If we go out and vote with women’s empowerment in mind, we can show that all of that rhetoric has no basis,” she said.