The DNP was established on 10 February 1949 as a merger of the Korea Democratic Party and groups that supported Yi Chong-chon (who headed a youth organisation) and Shin Ik-hee (a member of the National Association), with the new party holding 70 of the 200 seats in the Assembly.

[2] It supported the creation of a parliamentary republic, and in 1950 proposed a constitutional amendment to this effect, although it was defeated in the Assembly.

[2] In the 1950 parliamentary elections the party received the highest share of the vote, although at 10%, it won only 24 of the 210 seats in a parliament dominated by independents.

[2] It nominated Yi Si-yeong as its candidate for the 1952 presidential elections; he finished third with 11% of the vote.

The 1954 parliamentary elections saw the party's vote share fall to 8% as it was reduced to 15 seats.