ⓒYONHAP News

Ex-SMEs and Startups Minister Park Young-sun has been named the ruling Democratic Party's Seoul mayoral candidate in the April 7 by-election. 

The ruling Democratic Party announced on Monday that the former journalist turned politician led her rival Rep. Woo Sang-ho in the primary race by a wide margin, with 69-point-56 percent of the overall votes to his 30-point-44 percent.

Former Seoul Mayor Oh Se-hoon has been selected as the main opposition People Power Party's(PPP) candidate to run in the April Seoul mayoral by-election.

The PPP on Thursday announced the results of party primaries for mayoral posts in Seoul and Busan.

Oh was declared the winner of the primary against former four-term lawmaker Na Kyung-won. Oh won 41-point-64 percent of votes in a survey held on Tuesday and Wednesday, while Na secured 36-point-31 percent.

Ahn Cheol-soo, leader of the minor opposition People's Party, won a primary with independent candidate Keum Tae-sup. Oh and Ahn are expected to face off in a second primary designed to ensure that just one candidate represents all opposition parties in the election.