Hong Joon-Pyo, governor of the southern province of South Gyeongsang, became the Liberty Korea party's standard-bearer for the poll on May 9, securing 54 per cent of votes in a nationwide primary.
The 62-year-old prosecutor-turned-politician is renowned for his incendiary rhetoric and declared following his victory: "The time calls for a strongman with determination and a hot temper.
"The leaders of the four great powers are far-right nationalists, so the outlook will be gloomy for South Korea if a weak leftist government is established."
Park Guen-Hye was the party's candidate at the last poll -- when it was known as Saenuri -- and secured the largest vote share of any contender in South Korea's democratic era, but has since been impeached following a corruption scandal. She was arrested earlier Friday.
More From This Section
Hong languished in fifth place in a Korea Gallup poll published Friday, on just four percent support.
Four liberals were ahead of him, led by a former leader of the main opposition Democratic Party (DP), Moon Jae-In, on 31 per cent.
"Trump was elected although he was the least favoured candidate," he said on a television talk show last week.
He also said this week that if elected, he would meet Chinese President Xi Jinping before he talks with Trump.
Hong has sought to keep his distance from Park, describing her as "inept", and has already turned his fire on the DP's Moon, once the top aide to former liberal president Roh Moo-Hyun, who killed himself during a corruption investigation in 2009.
Critics say the investigation into Roh, who remains the most popular ex-president in the South, was politically motivated.