Over hundred thousand Likud members are expected cast their ballots at over a hundred polling stations on Thursday to determine the future of the party. Netanyahu's key rival in this primary is former interior minister and ally Gideon Sa'ar.
The conservative party, normally united, saw a split as Sa'ar built his line on criticism of Netanyahu over his failure twice to form a government which eventually pushed Israel in political hiatus, with the country currently headed to its third snap general vote in a year.
Netanyahu is also confronted by three corruption indictments.
At the moment, at least four conservative members of the Knesset have announced their open support for Saar.