SAN JOSE: Costa Rican voters are to cast ballots Sunday in the first stage of presidential elections that are being buffeted by a debate on gay marriage in the relatively well-off Central American nation.
A total 13 candidates are vying to succeed outgoing President Luis Guillermo Solis, who is constitutionally barred from seeking a second consecutive term.
Which way the 3.3-million-strong electorate will swing is unknown. Nearly 40 percent say they haven't yet decided, according to the latest survey.
That almost certainly means a second-round, runoff election eight weeks later, on April 1 -- Easter Sunday this year, and April Fool's Day.
Sunday's election will also choose a new legislative assembly.
The key issue seen swaying voters is same-sex marriage.
- Evangelical frontrunner -
Though prized by tourists drawn to its pristine beaches and jungles, Costa Rica is socially conservative and had stayed outside of the current debate that has seen several other Latin American countries accept legal unions of homosexuals.
But in January, the Inter-American Court of Human Rights -- located in Costa Rica's capital San Jose -- urged same-sex marriages to be recognized.
The decision is meant to be binding on states that are signatories to the 1969 American Convention on Human Rights, Costa Rica among them, and the current government indicated it was prone to do so.
But there has been resistance.
A Costa Rican man and his Venezuelan boyfriend tried to be the first gay couple to tie the knot, but were thwarted by the national notaries' council banning its members from carrying out such celebrations.
One previously obscure presidential candidate, evangelical lawmaker Fabricio Alvarado, jumped on the issue to reject homosexual marriage. He saw his ratings in the CIEP voter survey surge from a meager three percent to around 17 percent, ostensibly making him the frontrunner.
Just behind is Antonio Alvarez, a former lawmaker and a businessman from the PLN party that is the country's biggest and most traditional. Then comes Carlos Alvarado, from the ruling PAC party.
"Given his focus on social issues in a context of heightened concern over the economy, security, and corruption, Alvarado would likely struggle to win a second-round runoff against any of the other leading candidates," the Eurasia Group political analysis firm said in a briefing note last week.
- Corruption scandal -
Another candidate seen with a chance is Juan Diego Castro, a former security minister promising a crackdown on corruption and crime.
Rotsay Rosales, a professor at the University of Costa Rica, told AFP that the electorate appeared disenchanted with candidates who were "not very charismatic and not very convincing."
The high proportion of undecided voters suggested many were had not found a champion to address other concerns they held.
They included a corruption scandal called "cementazo" in which the state bank made irregular loans to a businessman with ties to judges and lawmakers so he could import Chinese cement, and rising security fears reflected in heightened gang activity and a record murder rate.
Those voters "who believe all politicians are corrupt" could turn to Castro, said a political analyst, Jorge Vega.
Castro's outsider status and provocative rhetoric have prompted some to liken him to Donald Trump, who confounded pundits to take the US presidency.
"The scenario is so volatile that anything could happen," Vega said.