Ex-Prosecutor General Yoon Seok-youl, the front-running opposition presidential contender, saw his approval rating lose ground to become on par with that of Gyeonggi Province Gov. Lee Jae-myung, a poll on prospective presidential hopefuls showed Monday.

According to the survey conducted on 1,004 voters nationwide by the Korea Society Opinion Institute on Friday and Saturday, Yoon from the main opposition People Power Party (PPP) garnered 28.3 percent of support, down 4 percentage points from a week earlier.

Gyeonggi Gov. Lee of the ruling Democratic Party (DP) saw his approval rating inch up by 1 percentage point to 28.4 percent, coming ahead of Yoon by a razor-thin margin of 0.1 percentage point.

Third place went to Rep. Lee Nak-yon from the DP, who had 16.2 percent, followed by ex-chief of the Board of Audit and Inspection (BAI) Choe Jae-hyeong from the PPP at 6.1 percent.

When asked who is most likely to win the presidency in the March 9 election, 34.3 percent of the respondents picked the Gyeonggi governor, while 33.4 percent selected Yoon. Rep. Lee had 15.2 percent.

The poll also put the approval rating for President Moon Jae-in at 44.5 percent, down 0.9 percentage point from a week earlier. Nearly 52 percent, however, gave a negative assessment of Moon's presidency.

The poll, commissioned by the radio news channel TBS, has a margin of error of plus or minus 3.1 percentage points with a 95 percent confidence level. (Yonhap)