South Korea's former opposition leader announced his Presidential bid today, joining the ranks of liberals looking to replace the country's conservative leader Lee Myung-bak. Chung Se-kyun of the Democratic United Party, who headed the centre-left party from 2008 to 2010, has become the fourth liberal heavyweight to declare candidacy for the December Presidential election.

Chung, a five-term legislator who served as Commerce Minister in the previous administration, said in a statement he will become the "Economy President" that people can trust. His rivals include Moon Jae-in, a senior advisor to the party, and Sohn Hak-kyu, who led the party after Chung stepped down.

The Presidential poll is slated for Dec.19. Lee is Constitutionally barred from seeking a second term.