Barak said he decided not to run "with a heavy heart," because it was still unclear whether there would be political mergers with Yesh Atid or Tel Aviv Mayor Ron Huldai's Israelis Party.
The only candidates who has declared they are running are MK Merav Michaeli and advertising executive Gil Beilin. Labor, Social Services and Social Equality Minister Itzik Shmuli has not decided whether to run. The deadline to join the race is Friday.