The country previously promised it would bring its deficit below 3% by next year.
The unions are also protesting against planned public sector job cuts and privatisations.
German police used pepper spray against thousands of anti-capitalist protesters in Frankfurt.
Trains and ferries were cancelled and hospital staff left their posts in Greece on Wednesday.
Spaniards marched to protest deep austerity, corruption & the privatisation of public services.
Rancorous vote on constitution makes Egpytians worry about the economy.