On the first congress of the Democratic United Party on 15 January 2012, Han was voted chairwoman of the supreme council of the party with 24.5 per cent support rate. The liberal party was created by a merger of the Democratic Party with the minor Citizens Unity Party, and is South Korea's main oppositional force. Han was elected to parliament in the April legislative elections, but the liberals did not manage to oust the ruling party and Han stepped down as DUP head on 16 April 2012. For three months the leaders of the two major Korean parties were women: Park Geun-hye of the Grand National Party and Han Myeong-sook for the DUP.