YRIZA-Progressive Alliance leader Alexis Tsipras announced the assembly of all party committees after his party's defeat in Sunday's elections.
Earlier, the main opposition leader conceded to Prime Minister Kyriakos Mitsotakis.
In a brief statement, Tsipras said the following:
"Winning and losing are both part of any struggle. The electoral result is extremely negative for Syriza. A short while ago I contacted Mr. Mitsotakis to congratulate him on his victory. Our party committees will convene immediately to evaluate the results. The election cycle is not yet over, since there will probably be a runoff, therefore we do not have time to spare. We must immediately make all changes necessary to fight the next critical and final electoral battle in the best possible terms. I want to thank from the bottom of my heart the hundreds of thousands of people who supported us with their votes, and above all Syriza's thousands of members and friends who fought the difficult electoral battle with us."