MK Meir Sheetrit became the fourth MK to resign from Tzipi Livni's Hatnua Thursday, in an announcement made during a press conference held in Tel Aviv.
Sheetrit has been active in the party and was, at one point, a presidential candidate running against President Reuven Rivlin.
But he, like other Hatnua MKs, has been said to be unhappy over Livni's pact with Yitzhak Herzog's Labor party, which pushed several Hatnua MKs down the Knesset mandate list.
Former Hatnua MKs Elazar Stern, David Tzur, and Amram Mitzna have each announced their resignation from the party, leaving simply Livni and former Environmental Protection Minister Amir Peretz on the Labor list - with Livni as #2 and Peretz as #8.
Both Mitzna and Sheetrit have made clear that they do not intend to join a different party, according to Haaretz. Stern, meanwhile, may be in talks to join Yisrael Beytenu, according to close confidantes.