Greece's international lenders last week approved the latest tranche of aid for Athens, but stipulated tough conditions in return for the assistance, including a dramatic reduction in the size of the country's civil service. Greece's two largest unions, which represent around 2.5 millions workers, responded by calling a 24-hour general strike, which saw trains, buses and flights cancelled.
Elena Panaritis, an economist at the Thought 4 Action think tank, said this week's unrest could threaten the stability of the country's coalition government, made up of New Democracy and Pasok.
"It shakes the whole structure of the political system," she told CNBC on Tuesday. "Political favors have been placing public sector people in specific jobs – and now the same political parties need to cut these jobs. So yes, it does generate a critical electric chair for both [parties]."
She added: "The question in the streets is: 'how long will they last?'"
The demonstrations come at an awkward time for Greek Prime Minister Antonis Samaras, just two days ahead of German Finance Minister Wolfgang Schaeuble's arrival in Athens.
The official visit on Thursday is expected to spark further protests, highlighting the wide-spread anger felt by the Greek public towards its international creditors and the reforms demanded in return for aid.
Greece's "troika" of lenders - the European Union, European Central Bank and International Monetary Fund - want to see 25,000 public sector workers placed in a so-called "mobility pool" by the end of the year. They will be given eight months to find work elsewhere in the civil service or face redundancy.