Moon Jae-in, former head of the Democratic Party, extended his lead in approval rating over the governor of South Chungcheong Province from the same party, among potential presidential candidates, a poll showed Friday.

According to the poll conducted by Gallup Korea, Moon posted an approval rating of 34 percent this week, up 2 percentage points on-week. The survey was conducted on 1,010 South Koreans with a margin of error of plus or minus 3.1 percentage points.
  Moon Jae-in, former head of the Democratic Party (Yonhap)
South Chungcheong Gov. An Hee-jung, on the other hand, managed to post 15 percent, down 6 percentage points over the cited period.

An has been suffering a drop in opinion polls after making a controversial remark last month where he said President Park Geun-hye intended to come up with reasonable policies, although she did not follow the rules and the system. Park was impeached by the parliament in December on corruption charges.

Rep. Ahn Cheol-soo of the minor People's Party posted 9 percent, trailed by Seongnam Mayor Lee Jae-myung and Acting President and Prime Minister Hwang Kyo-ahn with 8 percent each.

Rep. Yoo Seong-min of the Bareun Party's approval rating stood at a negligible 1 percent. (Yonhap)