Former Prime Minister Rep. Lee Nak-yon slipped in favorability ratings as a potential presidential candidate, but retained the top spot for the 12th consecutive month, a poll showed Tuesday.

The lawmaker from the ruling Democratic Party of Korea saw his support drop to 34.3 percent, down 5.9 percentage points from the previous month, according to pollster RealMeter.

Lee lost support most noticeably in Gangwon Province, where 25.7 percent of voters said they favored him, down 11.9 percentage points, the poll showed.

By age group, voters in their 20s showed the biggest decline of 11.5 percentage points, totaling 23.5 percent.

Preference for Lee among survey participants who categorized themselves as progressives also dropped by 8.5 percentage points at 52.7 percent, the poll showed.

The survey, commissioned by online media outlet Oh My News, was conducted among 2,537 eligible voters between May 25-29 nationwide and has a 95 percent confidence level with a margin of error of plus or minus 1.9 percentage points.

Despite the dip, Lee nudged Gyeonggi Province Gov. Lee Jae-myung, who came in second for the second consecutive month, by a large margin of 20.1 percentage points, according to the poll.

Former main opposition United Future Party Chairman Hwang Kyo-ahn, who stepped down upon the party’s defeat in parliamentary elections, ranked third at 6.8 percent, up 0.8 percentage points.

Prominent conservative politician Rep. Hong Joon-pyo, who is currently an independent, trailed behind garnering 6.4 percent preference, followed by Ahn Cheol-soo, chief of the minor People’s Party, and former Seoul Mayor Oh Se-hoon, according to the poll.

By Kim Bo-gyung (lisakim425@heraldcorp.com)