Papandreou's new government introduced several interesting reforms in the wake of its victory (legalization of civil wedding, new family law, nationalization of certain private companies, etc.).
The main opposition party, New Democracy, faced serious internal conflicts. Georgios Rallis was forced to resign after the defeat and he was succeeded by Evangelos Averoff, former minister under Karamanlis governments. In 1984 Averof resigned because of health problems and Konstantinos Mitsotakis became the new leader of New Democracy. Noteworthy, Mitsotakis and Papandreou were both centrists before 1967 and they belonged to the same party, George Papandreou's Center Union. Nevertheless, they were strong opponents and they never liked each other. Papandreou was calling Mitsotakis "a defector, an apostate", because in 1965 he defected from the ruling Center Union and participated in a new government pleasing to Constantine II, who had just accepted George Papandreou's resignation after a serious disagreement between the King and the prime minister.
^Verney, Susannah (March 2011). "An Exceptional Case? Party and Popular Euroscepticism in Greece, 1959–2009". South European Society and Politics (Routledge) 16 (1): 51–79. doi:10.1080/13608746.2010.538960.