Former Seoul Mayor Oh Se-hoon, a member of the main opposition People Power Party, announced on Sunday his candidacy for the Seoul mayoral by-election.

With Oh joining the race, the so-called “Big Three” from the opposition bloc -- including Ahn Cheol-soo, head of the minor opposition People’s Party, and Na Kyung-won, former floor leader of the conservative opposition -- are expected to compete for the title of unified candidate, who may be selected next month.

The former mayor, who previously vowed to run if Ahn did not join the People Power Party, said Sunday, “Unfortunately, however, it is now difficult to expect pre-integration.” Oh had called for the People Power Party and the People’s Party to merge before the by-election race.

Oh was elected Seoul mayor in 2006 and 2010. In 2011, however, he staked his position on a referendum to end free lunches for all elementary and middle school students, and stepped down as mayor when turnout was not high enough.

“In order to save Seoul in crisis, we need an experienced mayor who can perform CPR from the day after the election,“ Oh said in his announcement. “The Seoul mayor, who is elected through the by-election, has less than a year to work. It is impossible to properly grasp the vast organization and business of Seoul in that short time,” he said, adding that he has “a secret weapon of five years of administration experience that no other candidates have.”

“The city of Seoul has a population of 10 million, over 40 trillion ($36 billion) in annual budget and 45,000 government officials. It is like a small government in charge of all policies and functions, such as the economy and jobs, construction and transportation, housing and welfare, environment and culture -- everything excluding national defense,” he said.

“The moribund Seoul cannot afford to wait for trial and error and policy experiments of an amateur mayor or a one-year intern mayor.”

With Oh joining the race, the number of candidates from the People Power Party has increased to 10, including Na Kyung-won, Seocho-gu Mayor Cho Eun-hee, former lawmakers Lee Hye-hoon, Lee Jong-koo and Oh Shin-hwan, and former Songpa-gu Mayor Park Choon-hee.

The whole opposition bloc may number more than 12 when including Ahn Cheol-soo and former lawmaker Keum Tae-seop, who left the ruling Democratic Party.

Candidates for the People Power Party will be accepted from Monday. The final candidates will be confirmed in February after the preliminary and final competitions. In the preliminary race, citizen polls and party votes will determine the winner, with citizen polls counting for 80 percent and party votes for 20 percent. In the final race, citizen polls alone will decide the winner. 

Though there is widespread speculation that the “Big Three” will join forces to unify the conservative bloc, nothing has been confirmed yet. The unification process would involve selecting one candidate from different political parties to represent the bloc.

In the ruling Democratic Party of Korea, Rep. Woo Sang-ho is the only candidate who has announced his candidacy. Minister of SMEs and Startups Park Young-sun is expected to join the race when a ministerial reshuffle takes place.

On Sunday, front-runner Ahn visited the second district of Sajik, an underdeveloped residential area in Jongno-gu that has been designated as an urban readjustment zone, to listen to residents’ difficulties and seek ways to improve the residential environment and promote redevelopment.

Na held a press briefing to announce a “plan to support small business owners and self-employed people and to revitalize business management,” which includes an emergency relief fund worth 6 trillion won ($5.44 billion) that she had earlier pledged to set up.

By Shin Ji-hye (shinjh@heraldcorp.com)