Labor leader Shelly Yacimovich will face off against her political opponents at a party convention on Friday morning in Tel Aviv that is expected to be stormy.The convention will decide the date for the party’s next leadership race and whether to hold a special membership drive ahead of the primary.Yacimovich’s opponents drafted enough signatures from Labor central committee members to force a secret ballot vote that could help them defeat her proposal and pass theirs.Yacimovich’s proposal entails holding the election on November 21 without a special membership drive in advance. MKs Isaac Herzog, Eitan Cabel and Erel Margalit, her expected opponents in the race, all want to have such a drive but bickered over the past few days over a date for the primary.After considering dates in February and March, they ultimately decided on January 21, two months after Yacimovich wants the race to be held. Yaimovich’s associates said her rivals were not only divided but also confused.“Usually, a party chairman does everything possible to avoid holding a primary,” a source close to Yacimovich said. “Shelly wants to minimize time for the campaign to minimize bleeding in the party. This is the first time the opposition to a party leader is doing everything possible to avoid holding elections.”Yacimovich’s associates expressed confidence that her proposal will pass, because her supporters are against holding a membership drive that could bring corruption to the party. Her backers include a mix of elderly people in the kibbutz sector and young people from Tel Aviv.Her rivals said they would pass their proposal because the secret-ballot vote enables central committee members to vote without fear of angering Yacimovich, who controls the party’s funding in the October 22 municipal races in which many of the members are running. One possible future Labor leadership candidate suffered a major setback on Thursday when Attorney-General Yehuda Weinstein decided to expand an investigation into the role of former IDF chief of staff Gabi Ashkenazi in the Harpaz Affair that beset the process of choosing Ashkenzi’s succesor as army chief.