Greece:

The coalition government led the country to the parliamentary elections of May 2012. The power of the traditional Greek political parties, PASOK and New Democracy, declined from 43% to 13% and from 33% to 18%, respectively, due to their support on the politics of Mnimonio and the austerity measures. The leftist party of SYRIZA became the second major party, with an increase from 4% to 16%. No party could form a sustainable government, which led to the parliamentary elections of June 2012. The result of the second elections was the formation of a coalition government composed of New Democracy (29%), PASOK (12%) and Democratic Left (6%) parties.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What led to the loss of power of traditional Greek parties?
their support on the politics of Mnimonio and the austerity measures