The main opposition People Power Party's presidential candidate, Yoon Suk-yeol, saw his lead over ruling Democratic Party rival, Lee Jae-myung, narrowed to a margin of 3.9 percentage points, an opinion poll showed Thursday.

Yoon was leading Lee 42.3 percent to 38.4 percent in the survey by RnSearch, commissioned by Maeil Business Newspaper and its affiliated broadcaster MBN.

The 3.9 percentage point gap is smaller than a 5.4 percentage point margin in favor of Yoon seen in the previous survey two weeks ago.

Ahn Cheol-soo, the presidential candidate of the minor opposition People's Party, came third with 3.4 percent, followed by Sim Sang-jeung of the minor progressive Justice Party at 2.9 percent.

The latest poll was conducted on Tuesday and Wednesday on 1,031 voters nationwide. It has a margin of error of plus or minus 3.1 percentage points, with a 95 percent confidence level.

Of the respondents, 34.9 percent supported the main opposition party, while the ruling party had 30.8 percent support. (Yonhap)