Colombian presidential candidates, former defense minister Juan Manuel Santos and two-time Bogota mayor Antanas Mockus, are virtually tied for the May 30 election and are now deadlocked for a second round in June, a poll said, according to Reuters. Santos, an ally of President Alvaro Uribe, took 38 percent of intended votes while Mockus, who had surged with his anti-corruption message, won 36 percent, according to the poll by Centro Nacional de Consultoria, or CNC, released late on Thursday. Santos has regained ground in more recent polls to tie with Mockus, who soared from single digits in April in the race to succeed Uribe, a U.S. ally popular for his tough campaign against leftist rebels. It was the first time Santos had also tied with Mockus in the second round of voting. With no candidate securing the more than 50 percent needed to win outright this month, Mockus and Santos will have to face off in the June contest when both would win 47 percent of intended votes, according to the poll. In a CNC poll a week ago, Mockus won 38 percent and Santos 34 percent in the intended votes for the first round. In the second round, Mockus had won 50 percent against Santos with 43 percent in last week's CNC poll. Thursday's poll was carried out by telephone on May 10-13 with 3,000 eligible voters in 100 cities across the country and with a margin of error of 1.8 percentage points. Uribe steps down this year after two terms marked by his tough security stance and his pro-business approach. Violence, kidnapping and massacres from the long war have dropped sharply and foreign investment has soared. Both Santos and Mockus say they will continue Uribe's basic policies but with more attention to joblessness and social problems now more important than rebel violence to most Colombians. Both say they will seek to increase tax revenue to tackle Colombia's wide fiscal deficit. As Bogota mayor, Mockus was as known as much for his stand against corruption and his tight fiscal management as his often oddball approach to politics and philosophical style. He once used street mimes to shame Bogota residents into obeying laws. Santos was responsible for some high-profile successes against guerrillas and was once also finance minister. But analysts say he suffered from the fallout of corruption scandals in the Uribe administration.