In 1997 he was defeated by the Democratic Labor Party candidate for South Korea's 15th presidential election. He was defeated again in 2002 at 16th presidential election, and in 2007 for the 17th presidential elections. Between 1996 and 1997 he was Chairman of Korean Confederation of Trade Unions (KCTU). In 2000 to 2009 he was leader of Democratic Labour Party ().