Deputy Foreign Minister Danny Ayalon is the latest victim of the Yisrael Beitenu political reshuffle.
Party chairman Avigdor Lieberman, Israel's foreign minister, announced that Mr Ayalon would not form part of the next Knesset list for the January election.
The decision comes after two controversial party figures announced that they would also leave politics.
MK Anastasia Michaeli and Tourism Minister Stas Misezhnikov, both members of the Yisrael Beitenu party, gave vague reasons for their departure.