A presidential candidate who promised to end Colombia's long-running conflict in six months quit the race on Sunday, two weeks before elections likely to hand President Alvaro Uribe a second term.

Alvaro Leyva was one of six candidates struggling to make headway against the conservative Uribe, who remains popular because his tough security stance against leftist FARC guerrillas has helped reduced violence in the cities.

"To the surprise of my friends and many others, I want to announce the withdrawal of my candidacy for the presidency, in which I was deeply involved. I serve better as a symbol of peace," Leyva, who was registering about 2 percent support in recent polls, told reporters on the campaign trail.

Some 55 percent of Colombians tell pollsters they plan to vote for Uribe on May 28. Opponents say the 53-year-old president has concentrated on security at the expense of health, housing and education for families displaced by the 40-year conflict.

Leyva, a lawyer with the National Movement for Reconciliation, had attacked Uribe as the "candidate for war" and highlighted accusations that the president's security agency was infiltrated by right-wing paramilitaries.

But with Colombians grateful for better security, less kidnapping and lower crime rates in urban areas, opposition candidates have gained little traction.

Helped by U.S. financing, Uribe has led a campaign to push back the FARC and attack Colombia's massive cocaine trade that funds their insurgency. Thousands die each year in the violence involving the military, Marxist rebels and right-wing militia.