The second round of a leadership race for a nascent center-left political formation in the country is expected to attract more than 150,000 voters, which on a mostly rain-soaked Sunday will be considered a significant turnout.
The two candidates are Fofi Gennimata, the president of the once dominant social PASOK party and first round runner-up Nikos Androulakis, a current MEP.
Polling stations have been set up around the country.
In the first round, Gennimata picked up 70,679 votes (42.76 percent), and Androulakis 41,955 votes (25.38 percent).
Athens Mayor Giorgos Kaminis got 22,226 voters (13.45 percent), while centrist Potami party leader Stavros Theodorakis came in a disappointing fourth with 5,603 votes (9,44 percent). Another five contenders all received single-digit percentage points in terms of votes.
PASOK more-or-less dominated the Greek political scene after 1981, holding power between 1981 to 1989, then again from 1993 to 2004 and finally during a shorter stint from 2009 to 2011, whereby its election strength fizzled amid two successive memorandum bailouts.
Grouping together the country’s center-left, centrist and social democrat parties under one “big tent” formation is viewed by many political analysts in Greece as a direct threat to the current ruling leftist SYRIZA party, which itself went from low single-digit numbers to a convincing election victory of 36.3 percent in January 2015 on a populist campaign platform that promised to overturn austerity and tear up bailout agreements.