Amir Peretz, file
Amir Peretz, fileMiriam Alster/Flash90

Former Labor Party chairman and one-time Defense Minister Amir Peretz has announced his intention to challenge opposition leader Isaac Herzog for control of the party in primaries which are expected to be held in 2017.

Monday’s announcement marks the fourth time Peretz has run for leadership of the Labor Party, which is currently part of the Zionist Union joint list after deciding to run with the Hatnua faction.

No date has yet been set for Labor’s internal elections, and Peretz is the first declared candidate.

Aside from Peretz, Herzog is expected to run in the primaries, as are former Labor Party chairwoman Shelly Yachimovich and former venture capitalist MK Erel Margalit.

Recent polls have shown the Zionist Union losing much of its strength, a development that has encouraged rival Labor members to challenge Herzog for leadership of the party. According to a poll by Midgam released earlier this month, if elections were held today under Herzog’s leadership, the Zionist Union would fall from the 24 seats it won in 2015 to just 10 mandates.