臺北經濟文化代表處
Lee was elected to the Legislative Yuan in 1996. He then became the youngest convener of the Democratic Progressive Party (DPP) caucus in the legislature. Following DPP’s successful presidential election in 2000, Lee was appointed by President Chen Shui-bian to be the Deputy Representative of the Taipei Economic and Cultural Representative Office (TECRO) in the U.S. and then Secretary-General of the Executive Yuan. He was then named the DPP candidate for Taipei City's 2002 mayoral election, losing to incumbent mayor Ma Ying-jeou in a landslide.