SEOUL, April 7 (Xinhua) -- South Korean presidential archrivals had a close race in recent opinion polls with just a month left before the election.
According to a Gallup Korea survey released Friday, Moon Jae-in of the biggest Minjoo Party gained 38 percent of support, narrowly beating Ahn Cheol-soo of the center-right People's Party who garnered 35 percent.
It was based on a poll of 1,005 voters conducted between Tuesday and Thursday. The results have 3.1 percentage points in a margin of error.
Much of support for Moon's rivals in the primaries of the Minjoo Party moved to Ahn, the founder of the People's Party composed of defectors from the Minjoo Party.
Ahn's support jumped 6 percentage points compared with the previous week, while Moon's approval rating shed 2 percentage points.
Ahn, the software tycoon-turned-politician, threw his support behind Moon in the 2012 presidential election after abandoning his run for presidency. Moon was the runner-up to impeached President Park Geun-hye in 2012.
The primaries of five major political parties were wrapped up earlier this week. The presidential by-election, which was caused by Park's impeachment on March 10, is scheduled for May 9.
Hong Joon-pyo of the former ruling Liberty Korea Party gained 7 percent of support, trailed by Yoo Seong-min of its splinter Righteous Party who won 4 percent in approval scores.
Sim Sang-jung of the minor progressive Justice Party recorded 3 percent in her approval rating.
The prediction for the upcoming election results got much harder to make as Ahn rapidly absorbed support from conservative voters.
Conservative voters turned their backs from the traditionally conservative Liberty Korea Party, with which Park was affiliated, over her corruption scandal that led to her impeachment and arrest.
Support for the People's Party increased in accordance with the growing popularity for Ahn, according to the poll.
The People's Party earned 22 percent in support scores this week, up 6 percentage points from the previous week.
The Minjoo Party kept its top post with 40 percent of support, but it was down 5 percentage points from a week earlier.
The Liberty Korea Party and the Righteous Party garnered 8 percent and 4 percent each in approval scores, while the Justice Party won 4 percent.