BOGOTA (Reuters) - Colombia's presidential election will likely go into a closely fought run-off in which opposition candidate Oscar Ivan Zuluaga is seen locked in a statistical tie with incumbent President Juan Manuel Santos, a poll released on Thursday showed.
While Santos would lead the first round of the election on May 25 with 27.7 percent of the vote, against Zuluaga, with 23.9 percent, the anticipated run-off between them is neck and neck, the survey by Cifras y Conceptos showed.
Barring an extraordinary late-minute surge, neither contender is expected to clear the 50 percent threshold needed to avoid a June 15 run-off.
Right-wing Zuluaga, the chosen candidate of still-popular former President Alvaro Uribe, would win the second round with 34.2 percent of the vote, against the center-right Santos' 33.6 percent, according to the survey.
But Zuluaga's projected run-off lead is much less than the poll's 2.9 percent margin of error, which puts the two candidates in a statistical dead heat.
Santos and Zuluaga differ little on economic issues - both favor investor-friendly policies - so the choice for many voters is likely to come down to the candidates' position on ongoing peace negotiations with Marxist FARC rebels.
In a bid to end five decades of war, Santos began talks with the FARC, or Revolutionary Armed Forces of Colombia, at the end of 2012.
Santos has said his re-election is vital to completing the negotiations in Havana, where representatives of the FARC and the government have so far reached partial agreements on two of the five agenda points.
Zuluaga has said he would demand concessions, including a ceasefire, from the rebels before continuing talks, a condition FARC leadership has rejected. He has also talked about scrapping the negotiations.
Both campaigns were jolted by the resignations of key advisors last week, after allegations of bribery and spying prompted investigations by authorities.
Support for each of the other candidates in the contest - the Green Alliance's Enrique Penalosa, Clara Lopez of the left-wing Polo Democratico and the Conservative Party's Marta Lucia Ramirez - was at or below 10 percent.
The proportion of voters who plan to choose none of the candidates on the ballot, via a blank or protest vote, fell to 11.5 percent from 16.8 percent in the last poll.
The survey of 2,762 respondents in 62 municipalities was conducted between May 9 and May 12.
(Reporting by Julia Symmes Cobb and Luis Jaime Acosta, Editing by W Simon)