A new poll on prospective presidential contenders released Friday showed former Prosecutor General Yoon Seok-youl with a slight edge over his ruling party rival, Gyeonggi Province Gov. Lee Jae-myung.

In the survey by Gallup Korea, Yoon received 25 percent of support, up 4 percentage points from a month before. He overtook Lee, whose rating stayed put at 24 percent.

The survey conducted from Tuesday to Thursday was the first opinion poll after Yoon, with no party allegiance, announced his intention to run in next year's presidential election on the day.

Lee of the ruling Democratic Party (DP) also launched his presidential bid Thursday.

Their gap of 1 percentage point is within the survey's margin of error of 3.1 percentage points. It was conducted on 1,000 people aged 18 and older around the country.

Lee Nak-yon, formerly a prime minister and DP leader, came in third with 6 percent, followed by five minor contenders, who tied with 2 percent -- former Board of Audit and Inspection chief Choe Jae-hyeong, the main opposition People Power Party's leader Lee Jun-seok, former Prime Minister Chung Sye-kyun, PPP lawmaker Hong Joon-pyo and former Justice Minister Choo Mi-ae.

Support for the DP and the PPP were the same at 32 percent. The DP's support was unchanged from a month before, while the PPP's score rose 2 percentage points, apparently driven by the ascent of young new leader Lee Jun-seok.

The approval rating for President Moon Jae-in slid 2 percentage points to 38 percent, while disapproval was up 3 percentage points to 54 percent. (Yonhap)