The process of electing a new leader for main opposition SYRIZA-Progressive Alliance began early on Sunday. Ordinary members and anyone over 15 who wants to register as a party member are free to cast their vote at any of the 570 polling centres the country. The polls opened at 8:00 in the morning and will close at 20:00 on Sunday night.
Prospective voters are free to join the party at the polling stations on the day of the elections, if they have not already done so. There is a two-euro fee for participating in the election process and voters must have a valid ID (police ID card, passport, driving licence, health passbook, residence permit, visa or blue certificate). Immigrants and those under 17 must have a legal document verifying their identity and their AMKA.
 Those abroad can participate in the election electronically, between 8:00 and 20:00 on Sunday, but must be registered members and have registered with the isyriza platform by 14:00 on September 14.
If a second round is needed based on the results of this election, this will take place on Sunday, September 24.
There are five candidates vying for election as party leaders. Former minister Effie Achtsioglou cast her vote at the Peristeri polling station (Peristeri Town Hall Exhibition Hall, Karatheodori 1) at 10:00. In statements afterward, she noted that this was a great day, a day for the renewal of the modern Left and said: "Yesterday, Mr. Mitsotakis told us that his plan for the next years is for us to survive. We won't take him up on it. Today we send the first message and tomorrow we demand the life that we deserve."

Rival candidate Nikos Pappas voted in Kaisariani, with the message: "Today we vote, tomorrow we change." SYRIZA-PA leadership candidate Stefanos Tzoumakas cast his vote in Kallithea on Sunday, with an appeal to party members and all democratic and progressive citizens to participate in the election process "so that we can change course".

The fourth candidate to cast his vote was Stefanos Kasselakis, at the same polling centre in Peristeri as Achtsioglou, where he noted that the country "deserves to have a progressive government soon," and said he was deeply moved by the unexpectedly large turnout.

The last candidate to vote was Euclid Tsakalotos, in Nea Ionia, who said: "This is an important day, an important day for SYRIZA and society, and an important day for the people of the Left."