New Democracy

The result was a resounding success for Tsipras' high-risk gamble when he resigned as prime minister last month and triggered an early election, barely seven months into his four-year term, in order to face down an internal Syriza rebellion over his policy U-turn to accept painful austerity measures in return for Greece's third international bailout.

Three surveys published Friday show the two parties roughly level within the margin of error, with the winner likely to require the support of two smaller parties to form a coalition government.

Syriza leader Alexis Tsipras resigned as prime minister and called the snap election last month after reaching an agreement with eurozone creditors for a third bailout that triggered a split within his party.

Alexis Tsipras resigned last month, triggering Sept. 20 elections, barely eight months into his four-year term following a rebellion by Syriza hardliners objecting to his agreement to creditor-demanded tax hikes and spending cuts in return for a third bailout.

Recent opinion polls show Syriza in a dead heat with opposition New Democracy, but with neither winning enough seats to form a government.