Although the Democratic Union, a coalition of centrist parties, received a slim plurality of votes, the conservative governing party, the National Radical Union, won the most seats due to a complex and controversial electoral system enacted by Karamanlis. A "first past the post" system was applied in the rural constituencies where the ERE was expected to gain a plurality, while proportional representation was reserved for the urban constituencies, where the Democratic Union was expected to lead.[2][3] As a result, the Democratic Union came up 19 seats short of a majority.
In 1955, Karamanlis was chosen by the King Paul I as successor of prime minister General Alexandros Papagos, who had just died. The decision was controversial, as Karamanlis was not a leading member of Papagos' party, and caused the vehement reactions of the party's two most prominent members, Stefanos Stefanopoulos and Panagiotis Kanellopoulos.
Nevertheless, Karamanlis, thanks to the support of the royal family and his own dexterous handlings, managed to establish himself as a strong leader. After stabilizing his leadership, he dissolved the Greek Rally party and created his own conservative right-wing party, the National Radical Union, which also comprised some prominent centrists (Evangelos Averoff, Panagiotis Kanellopoulos, Konstantinos Tsatsos) and went on to dominate the Greek political scene for the next 8 years.