With Oh Se-hoon expected to step down as Seoul mayor, rival political camps were pondering Thursday over who among their members has the best shot at winning the post, which some say is second most influential in Korea after the president.

In media reports, a handful of names are being floated as possible candidates. 

They include Reps. Na Kyung-won and Won Hee-ryong from the governing Grand National Party, who were defeated by Oh in last year’s GNP race for the Seoul mayor candidacy.

On the opposition’s side, the list of potential candidates is longer, with some already announcing their bid.

Rep. Chun Jung-bae, who served as Justice Minister under the previous administration of late President Roh Moo-hyun, made official his intention to run in a by-election if it’s held.

“I will run in the by-election, if Oh resigns,” the lawmaker of the main opposition Democratic Party told a press conference.

Other than Chun, several more DP lawmakers were considering joining the race, including Park Young-sun, Jun Byung-hun, and Choo Mi-ae. Park and Choo are both women.

Outside the parliament, lawyer-turned civil activist Park Won-soon was mentioned as a potential candidate.

Some speculate that the main opposition bloc will have to put up Han Myeong-sook to seize Seoul from the ruling camp. Han, who was Korea’s first female prime minister, came close to winning the mayoral election in 2010. She lost to incumbent mayor Oh by a margin of just 0.6 percentage point.

Former lawmakers Kim Han-gill and Lee Kye-ahn are said to be preparing to run for the Seoul mayor.

President Lee Myung-bak served as Seoul mayor before taking office as president in 2008.

By Lee Sun-young (milaya@heraldcorp.com)