He also claimed to be the only candidate capable of beating front-runner Moon Jae-in of the liberal Democratic Party on May 9.

"I will be open and honest," the former software mogul said. "If (your) aim is not to beat Moon Jae-in but to create hope for the conservatives, please vote for Yoo Seong-min."

He added, "Those of you who would like the progressives' voice to be heard louder, please vote for Sim Sang-jeung."

While Moon has maintained a clear lead with support of around 40 percent, voters who are opposed to the liberal have been seen shifting their support from Ahn to Hong Joon-pyo of the conservative Liberty Korea Party, the former ruling party affiliated with impeached president Park Geun-hye.

"Yoo Seong-min is a respectable conservative candidate. If I'm elected, I will certainly join hands with him. I will ask him to help me overcome the economic crisis," Ahn said. On Sim, he said she is the pride of progressives.

Speaking to reporters on the campaign trail in Gumi, 261 kilometers southeast of Seoul, Ahn elaborated that he and Yoo have similar economic policies. In particular, he expressed support for Yoo's election pledges to ensure employees don't work overtime and ban superiors from giving work-related orders via social networking services.

But on Moon and Hong, Ahn said they are "the past." They will bring division and conflict throughout their terms, he claimed.

"Conservatives are people who value the state and the Constitution, and believe in the value of a nation's dignity," Ahn told reporters in Gumi. "Hong doesn't fit that description at all."

Under Moon, the nation will be divided for the next five years, consuming all of its energy and breaking down in the process, Ahn claimed.

The two share a bitter past of competing for liberal votes ahead of the 2012 presidential election. Ahn dropped out in support of Moon, who then lost to Park.

Earlier Thursday, Ahn embarked on a campaign to rally supporters only on foot and via public transportation until the day before the election. (Yonhap)