Santos holds lead in Colombia election opinion poll but rival gains

BOGOTA (Reuters) - Colombia's President Juan Manuel Santos maintained his clear lead in voting intentions ahead of May 25 elections, a Gallup poll published on Tuesday showed, but his nearest rival, Oscar Ivan Zuluaga, continued to gain support. Santos would win 32 percent of the vote, down half a point from the pollster's March survey, while Zuluaga, the anointed candidate of still-popular former President Alvaro Uribe, jumped 5 percentage points to 20.5 percent. Santos would beat Zuluaga in a second round of voting by 46 percent of votes versus 34 percent for his rival. Though all leading candidates appear to differ little on broad economic themes, a choice between Santos and Zuluaga is likely for many voters to come down to who's approach to ending a five-decade conflict with leftist guerrillas they prefer. Santos initiated talks with the Revolutionary Armed Forces of Colombia at the end of 2012 and the negotiations have made slow but promising progress. Zuluaga has indicated he would likely call the talks off or impose tougher conditions under which the government would be prepared to negotiate. Like Zuluaga, Santos gained a lot of support from the public backing of then out-going president Uribe, who decimated the guerrilla's ranks during his two mandates in office with support from the United States. Santos' decision to engage with the FARC in peace talks has since turned the two bitter enemies. Support for the Green Alliance's candidate, and former Bogota mayor, Enrique Penalosa fell to 10.1 percent of voting intentions down from 11.3 percent last month, causing him to slip to fourth place behind the Conservative Party candidate Marta Lucia Ramirez who has 11.2 percent support. Clara Lopez of the left-wing Polo Democratico came last in the poll with 7.1 percent of voting intentions, down from 8.6 percent in March. The percentage who plan to make a blank or protest vote by choosing none of the candidates, fell 4 percentage points to 15.9 percent of voters. The survey of 1,200 respondents in 50 different towns carried out between April 23 and April 27, has a 3 percent margin of error. (Reporting by Peter Murphy; Editing by Michael Perry)