IBAGUE, Colombia (AP) — The campaign rally feels like a cross between a civics lecture and a revival meeting. The bespectacled former university rector with an Amish-style beard wields a pencil like a baton as he delivers his message: Education, not weapons, must drive change in a country wracked by violence.

“Mi profesor! Mi presidente!” comes the roar from a sea of mostly youthful Green Party supporters waving sunflowers and chanting adoration for Colombia’s newest political sensation.

Antanas Mockus’ unorthodox methods and colourful campaign have catapulted him from fringe status into a statistical dead heat with the former defence minister, Juan Manuel Santos, in Sunday’s election for president of Colombia, Washington’s top ally in South America.

The sudden rise in the polls of this political outsider — from three per cent in March to well over 30 per cent now — is giving Colombians what could be their most riveting election in decades.

A victory for Mockus, the son of Lithuanian immigrants, would make him the world’s first Green Party president — though his emphasis is more on clean government than clean environment. If no candidate gets a majority, the top two vote-getters will face off in a June 20 runoff.

Mockus, 58, won plaudits as a two-time Bogota mayor by dressing up as a spandex-suited “Super Citizen” and dispatching mimes to shame traffic scofflaws. At his rallies, he stresses the sanctity of public coffers, the virtues of paying taxes — which he says he’d raise. He directly addresses drug traffickers: The easy money isn’t worth an abbreviated life.

“Our campaign is the freshest, most improvised and creative ever,” the mathematician tells supporters in Ibague, which like most Colombian provincial capitals has long been controlled by machine politics.

Santos follows a more traditional, timeworn electoral script.

A Cabinet minister in three administrations who is also 58, Santos is running for elected office for the first time and stresses his close association with Alvaro Uribe, the popular, termed-out president who leaves office August 7.

As Uribe’s defence chief from 2006-2009, Santos helped knock the wind out of the leftist Revolutionary Armed Forces of Colombia, or FARC, Latin America’s last remaining rebel army. For that, Santos is deeply appreciated along the Caribbean coast, where ranchers and banana and African palm growers feted him last week.

Before Uribe’s election in 2002, the FARC routinely kidnapped people at roadblocks in the region, marching their victims into the hills while dispatching relatives for ransom. The highways are safe now.

In Aracataca, childhood home of Nobel Prize-winning novelist Gabriel Garcia Marquez, Santos kissed women on the cheek, wrapped his arms around men for group photos and was serenaded by an eight-year-old siren named Salome.

“With me you can sleep peacefully,” Santos assured them.

Campaign backers bused in some 100 people for a nearby rally, feeding them a free lunch. Rosa Elena Delgado, a 55-year-old cook in Aracataca, said the region’s long tradition of vote-buying wasn’t going to end anytime soon.

“People need that sack of cement,” she said. “No one is going to do away with that.”

Mockus says he would like to.

“I came because I wanted to. Nobody paid me,” is among the chants he employs to whip up the faithful at rallies.

The pro-Mockus “Green Wave” has been surging ever since Santos’ Unity Party — the strongest in Uribe’s governing coalition — won the most seats in March 14 congressional elections.

Though Uribe’s approval rating still hovers around 70 per cent, his legacy is threatened by a raft of scandals: Prosecutors say soldiers killed more than 1,000 innocent civilians during his tenure, while Uribe advisers allegedly ordered illegal spying on judges, journalists and human rights workers. And well-heeled Uribe backers received millions of dollars in irrigation subsidies intended to help needy farmers.