Since the Civil war (1946-49) but even more after that, the parties in the parliament were divided in three political concentrations. The political formation Right-Centre-Left, given the exacerbation of political animosity that had preceded dividing the country in the ’40s, tended to turn the concurrence of parties into ideological positions.

In the beginning of the 1950s, the forces of the Centre (EPEK) succeeded in gaining the power and under the leadership of the aged general N. Plastiras they governed for about half a four-year term. These were a series of governments having limited manoeuvre ability and inadequate influence in the political arena. This government, as well as those that followed, was constantly under the American auspices. The defeat of EPEK in the elections of 1952, apart from increasing the repressive measures that concerned the defeated of the Civil war, also marked the end of the general political position that it represented, namely political consensus and social reconciliation.

The Left, which had been ostracized from the political life of the country, found a way of expression through the constitution of EDA (United Democratic Left) in 1951, which turned out to be a significant pole, yet steadily excluded from the decision making centres. After the disbandment of the Centre as an autonomous political institution, EDA practically expanded its electoral influence to a significant part of the EAM-based Centre-Left.