Three opinion polls released Monday showed mixed results for rival presidential candidates Lee Jae-myung and Yoon Suk-yeol.
In a survey conducted by Realmeter, Yoon of the main opposition People Power Party (PPP) overtook Lee of the ruling Democratic Party (DP) as frontrunner with 40.6 percent vs. 36.7 percent.
Two other polls, released by Next Research and Embrain Public, showed Lee maintaining his lead over Yoon.
In the Realmeter poll conducted on 3,031 adults from Jan. 9 to 14, Yoon gained 6.5 percentage points from the previous week, while Lee lost 3.4 points.
Their gap of 3.9 percentage points was outside the margin of error of plus or minus 1.8 percentage points at a 95 percent confidence level.
In the previous survey, Lee was ahead of Yoon by a margin greater than the margin of error.
Source: Yonhap News Agency