Former head of the Labor party, Amir Peretz, addressed a letter to recently-elected party chief MK Merav Michaeli demanding an apology.
Peretz's lawyer stated that Michaeli had spread false accusations during the primaries campaign, alleging Peretz was preventing members of the party from taking part in the elections.
Peretz is insisting Michaeli issues a formal apology, threatening to file a law suit if she fails to comply.