This compilation image shows (from L to R) presidential candidates Lee Jae-myung, Yoon Suk-yeol, Sim Sang-jeung and Ahn Cheol-soo. (Yonhap)

Main opposition presidential candidate Yoon Suk-yeol is leading his ruling party rival Lee Jae-myung with 42.9 percent public support to 38.7 percent, a survey showed Sunday.

Yoon of the People Power Party gained 1.3 percentage points from a week ago, while Lee of the Democratic Party lost 0.4 percentage point, according to the Realmeter survey conducted on 3,043 adults from last Sunday to Friday.

The gap between Yoon and Lee widened to 4.2 percentage points from the previous week's 2.5 percentage points. The latest survey had the margin of error of plus or minus 1.8 percentage points at a 95 percent confidence level.

Ahn Cheol-soo, the presidential candidate of the minor opposition People's Party, was in third place with 8.3 percent support, followed by Sim Sang-jeung of the minor progressive Justice Party with 3.2 percent.

Asked to pick the candidate most likely to win, 49.4 percent chose Yoon, while 41.3 percent picked Lee. (Yonhap)

For more information regarding the survey results go to the National Election Survey Deliberation Commission homepage.