The Grand National Party was divided over who should be their mayoral candidate as opposition parties took a step closer to fielding a unified contender after respected entrepreneur Ahn Cheol-soo declared support for an opposition canidate.

In a Gallup poll of some 1,000 Seoul citizens earlier this week, nearly 40 percent said they would vote for Ahn. Second-place went to GNP’s Rep. Na Kyung-won, with 13 percent, closely followed by the opposition’s Han Myeong-sook with 10.9 percent.

Some within the GNP back Na, a former party spokeswoman who was elected one of the seven members of the party’s decision-making supreme council in July, while others insist they should look for someone from outside.

Pointing to a recent survey in which 72 percent of respondents picked administrative capabilities as the most important requirement for Seoul mayor, Rep. Lee Hye-hoon of the GNP called for someone outside the party with strong administrative experience.

Among those tapped are Prime Minister Kim Hwang-sik, ex-premier Chung Un-chan, former culture minister Yu In-chon, president of Hansun Foundation Park Se-il and ex-minister of home affairs Maeng Hyung-kyu.

A group of GNP’s rookie lawmakers said Wednesday candidates invited from outside should have to compete with contenders from within the party.

GNP secretary general Rep. Kim Jung-kwon said the party will soon finalize schedules for the by-election and all options were open regarding intraparty competition.

Opposition parties, meanwhile, launched a council named “Innovation and Integration” to push for selecting a unified candidate.

Main opposition Democratic Party leader Sohn Hak-kyu said Ahn’s support of civic activist Park Won-soon has added momentum to electing a unified opposition candidate.

“Victory is wide open for the DP in the Seoul mayor election,” Sohn said in a meeting of the party leadership on Wednesday.

Han, currently the opposition’s frontrunner, met with Park and Moon Jae-in, former top aide to ex-president Roh Moo-hyun, on Tuesday and agreed to cooperate for unified candidacy against the GNP.

The DP’s Rep. Jun Byung-hun withdrew his mayoral bid on Wednesday, saying he was shocked by the so-called “Ahn Cheol-soo syndrome.”

In a poll on likely presidential candidates conducted immediately after Ahn declared his intention not to run, Ahn garnered a support rating of 43.2 percent, beating the GNP’s strongest presidential hopeful Park Geun-hye, who received 40.6 percent.

In response to reporters’ questions regarding the poll results Wednesday morning Park simply said the “situation” should be turned into an opportunity for a new start in Korean politics.

By Kim So-hyun (sophie@heraldcorp.com)