Main opposition New Democracy (ND) party leads ruling SYRIZA by 16 percentage points in the latest opinion poll published on Monday.
The poll was presented on the prime-time newscast of Athens-based Skai TV and conducted by the University of Macedonia's political studies department.
Specifically, center-right ND was given 32.5 percent of respondents' preferences to 16.5 percent for leftist SYRIZA.
The figures show a slight decrease for both parties from the corresponding poll by the same firm in April 2017, where ND received 33 percent and SYRIZA 15.5 percent.
In terms of other parties, ultra-nationalist Golden Dawn (Chryssi Avgi) and the Communist Party (KKE) garnered 7.5 percent of respondents' preferences. The only other party above the 3-percent threshold is a PASOK-led socialist group.
The "don't know/won't answer" portion reached 14.5 percent.
Asked who is more qualified to be prime minister, 49 percent of respondents said "neither"; 30 percent said ND leader Kyriakos Mitsotakis and 19 percent for current PM Alexis Tsipras.
ND, however, enjoys an overwhelming lead over SYRIZA on the question of who respondents believe will win the next election, whenever it is held and regardless of who they support: with 69 percent favoring ND and 12.5 percent SYRIZA.