Labor chairman Ehud Barak will return from Annapolis on Thursday and go straight to a meeting of the party's executive committee, where his predecessor, MK Amir Peretz, intends to lead a rebellion against Barak's proposed changes in the Labor constitution. Peretz is furious at Barak for proposing changes that would give the party chairman more power to select Labor's next Knesset list. Peretz has warned that he would go to outside courts to stop the changes and perhaps even split the party. "Barak is maneuvering for a hostile takeover of Labor to make it a party of one person," Peretz told The Jerusalem Post. "Legally, there has to be another election for party head before the next general election. I told [Barak's people] that they are causing a rift in the party. I'm not afraid of a rift, but they should be. If he wants to remake Labor into a new party again like he did with One Israel, he can leave Labor and form his own party." The dispute began last week when Peretz met with Barak's ally, Labor constitution committee head Moshe Shahal. According to Peretz, Shahal outlined Barak's proposal, which he said included ending Labor's current system of electing MKs via primaries among 100,000 members and instead reinstituting a small "ranking committee" dominated by the party chairman, which used to decide the party's Knesset list. Peretz said Barak's proposal also included empowering the party chairman to reserve two slots among each 10 Knesset candidates for his own nominees, canceling slots on the list reserved for immigrants and candidates from poor sectors, allow the ranking committee to select mayoral candidates and dismantling the party's appellate court. Barak also angered Peretz by trying to make the changes before new Labor institutions are elected to replace institutions whose term has ended. He said Shahal told him the changes could be voted on by the membership and amendments could be suggested and voted on via the Internet. "I told Shahal that he cannot make these changes when all of Labor's institutions are illegal," Peretz said. "Labor members in Yeroham don't have Internet access. He can't make this an Internet party. They say the primary system is corrupt, but there are better ways to fight corruption. The chairman himself was elected via corruption and there is still the cloud of a police investigation hanging over his head." Barak's plan met strong opposition when Shahal introduced it to a meeting of the constitution committee on Sunday. The executive committee will not vote on the matter on Thursday, but the debate is expected to be a key test of Barak's leadership. Social Welfare Minister Isaac Herzog, who is a close Barak ally, accused Peretz of exaggerating the changes that Shahal proposed. He said the party needed a new constitution and Shahal spoke to legal experts to determine what changes were needed. Herzog said he supported the changes even though they could cause him political harm as a candidate who is popular with Labor members and finished in the top slot in the last primary. He said it was necessary to empower the party chairman to help the party. "The primary system will not be canceled," Herzog said. "They are trying to sow panic and ignite a conflagration, but this is a democratic party and it's impossible for the chairman to take control of everything in the party." Labor Secretary-General Eitan Cabel said it was necessary to change the party constitution before the election for new institutions, because it would not make sense to elect representatives to the bodies and then decide to cancel their existence. He said he supported allowing the party chairman to bring in new and attractive candidates from outside politics, as Kadima did. "Everything will be done above board," Cabel said. "There is no reason to shout. Anyone can propose anything, but there is no chance that the ranking committee will return. It's just not going to happen."