Papandreou had formed an interim government just after the legislative elections of 1963, in order to carry out new elections, because no party had the absolute majority in the Parliament. The Greek people voted for a strong and robust government, offering the Center Union a landslide victory.
Another reason for the landslide victory of the Center Union was the indirect support for the centrists by the United Democratic Left (ΕΔΑ), which turned intentionally a part of its electorate towards the Center Union. It was the antipathy towards the conservatives that brought the two parties of the center-left closer.
Just after the elections, Georgios Papandreou formed his first solid government, which would last till 1965, when a new political turmoil, the so-called Apostasia (lit. "defection"), namely a fierce confrontation with King Constantine II, caused its fall and the appointment of a series of weak governments, comprising centrist defectors and supported by the National Radical Union and King Constantine II.
The elections of 1964 were the last before the enforcement of a military dictatorship, which exploited the endless political unrest.