Representatives of the Democratic Party of Korea and Lee Jae-myung say, ``The by-election for Gangseo-gu mayor is a prelude to the government's trial...we must win'' - South Korea

Representatives of the Democratic Party (opposition) along with Lee Jae-myung said on the 28th regarding the by-election for the mayor of Gangseo-gu, Seoul city, ``We must win as this is a prelude to next year's general election, which is an election to judge the government.