A recent poll showed that a runoff is expected in Costa Rica's upcoming presidential elections scheduled for Sunday. The candidate of the ruling National Liberation Party (PLN) Johnny Araya leads the voting preference with 17.4 percent, closely followed by the center-left Broad Front (FA) candidate Jose Maria Villalta, with 14.4 percent, according to a poll released by the University of Costa Rica (UCR) on Wednesday. The poll by the UCR's Political Science Research and Studies Center (CIEP) has a margin of error of 3.46 percent, so Araya and Villalta are locked in a dead heat. Villalta is also closely followed by the candidate of the Citizen's Action Party (PAC) Luis Guillermo Solis, who is in the third place with 11.6 percent. The candidate of the Libertarian Movement (ML) Otto Guevara is in the fourth place with 7.3 percent, while Rodolfo Piza from the Social Christian Unity Party (PUSC) is in the fifth place with 3.4 percent. With just four days to go before the elections, the number of undecided or swing voters is at a high 33.4 percent. The number of swing voters presents a very unpredictable scenario for Sunday's elections and creates a high probability of a second round, to be held on April 6. According to the country's constitution, a candidate is required to gain at least 40 percent of the popular vote to win outright, or the top two candidates will compete in a runoff. A total of 800 Costa Rican citizens were surveyed for the CIEP poll between Jan. 20 and 27.