Syriza has said it would seek to renegotiate the terms of the bailout, putting it on a collision course with Greece's international loan supervisors – the International Monetary Fund, the European Commission and the European Central Bank – and potentially jeopardizing Greece's economic recovery and access to more aid.
Read MoreEurope gets ready for another Greek drama
In addition, there are concerns that a Syriza win could lead to Greece exiting the euro zone, if the party does what it has promised and tears up the country's bailout agreement.
The German government is even preparing for such an eventuality, according to speculation in the German press this week.
Read MoreGermany, France take calculated risk with 'Grexit' talk
Syriza certainly shows no signs of attempting to mollify the rest of the euro zone, or indeed, the Greek establishment. One of the party's senior economists, George Stathakis, told the Financial Times on Tuesday that the party's priority was to tackle Greece's powerful businessmen that are seen by Syriza as too closely connected to the political elite.
"The oligarchs are high on our agenda… They will be a priority for action," he said, adding that industries where oligarchs are active, including the domestic media, state procurement and real estate, would be scrutinized.