The executive committee of President Recep Tayyip Erdogan's ruling party on Monday unanimously agreed to send former premier and party member Ahmet Davutoglu to a disciplinary board for dismissal, local media reported.
The decision came after a nearly five-hour meeting of the central executive committee of the Justice and Development Party (AKP) chaired by Erdogan, the Hurriyet newspaper reported on its website.
A leading AKP figure who served both as foreign minister and prime minister, Davutoglu has recently accused the party of deviating from its core principles.
His criticism included the party's insistence on a rerun of the Istanbul vote after the AKP lost the city to the opposition in March local elections, as well as the removal of three mayors in eastern Turkey on terror-related claims.
The party's move to expel the ex-premier comes as other former allies have fallen out with Erdogan including former president Abdullah Gul and former deputy prime minister Ali Babacan - both founding AKP members.
Babacan quit the party in July citing "deep differences" over policy and said Turkey was in need of a "new vision".
He is expected to launch a new political party.