The floor leader of the main opposition Democratic Party called on President Yoon Suk Yeol on Thursday to take responsibility for the ruling party's defeat in a crucial by-election in Seoul, starting with a complete overhaul of the Cabinet.

Jin Kyo-hoon of the Democratic Party was elected earlier in the day to represent Gangseo Ward in Seoul, defeating his rival from the ruling People Power Party, Kim Tae-woo, by a larger-than-expected margin of 17.15 percentage points.

"The dismissal of the prime minister, the firing of the justice minister, and the withdrawal of unqualified people (nominated for the Cabinet) should be the starting point," said Rep. Hong Ihk-pyo, the Democratic Party's floor leader, during a party meeting.

Although the election only determined who would become one of Seoul's 25 ward chiefs, Wednesday's by-election was widely viewed as a crucial gauge of voter sentiment leading up to the parliamentary election in next April.

"The results of this election represent the people's firm judgment on the Yoon Suk Yeol administration's unchecked authority and signify a victory for the people wishing for a new Gangseo Ward," Hong said.

Hong further urged Yoon to carry out a complete overhaul of the way he runs the government, saying it is time for him to reply. (Yonhap)