Prime Minister Ehud Olmert agreed Wednesday night to allow the winner of September's Kadima primary to form a new government and immediately replace him, senior sources in the party said, confirming a report on Channel 1. After three days of negotiations conducted by MK Tzahi Hanegbi, head of the Kadima steering committee, with Olmert and the party's four leadership candidates - Foreign Minister Tzipi Livni, Transportation Minister Shaul Mofaz, Public Security Minister Avi Dichter and Interior Minister Meir Sheetrit - they agreed on a three-page deal according to which whoever wins the primary will automatically become the Kadima candidate for prime minister in the next general election. Livni had been making those demands because she was worried that Olmert would try to stay in power after the primary, and would insist on holding another primary ahead of the next general election. All four of the candidates agreed that the primary would be held between September 14 and 18, and if a runoff is needed between the top two finishers that it would take place no later than September 25. Olmert's associates said he had agreed to the deal because it guaranteed that in the likely scenario that the victor in the primary was unable to form a government, Olmert would remain prime minister until the next general election, which would likely not take place until March of 2009. Despite the agreement, the dates will not be officially confirmed at the Kadima council meeting at the party's Petah Tikva headquarters on Thursday night. Olmert will not attend the meeting but the four candidates to replace him are all expected to speak at the event. Dichter intends to use his speech to warn against the ramifications of Olmert remaining Kadima's leader, a message he first delivered at an ill-fated press conference last week coinciding with the bulldozer terrorist attack in Jerusalem. The council will vote to ratify the party's agreement with Labor, which requires Kadima to hold a leadership primary by September 25. The party's constitution will be changed at the meeting to enable the race to take place. The council will also set a July 31 deadline for new members to join the party to be able to vote in the race. The votes on those issues will begin on Thursday night, but council members will be able to come to the headquarters to vote over the next few days. The extra time was given because of the low attendance expected for the meeting. The proposal is expected to pass by a wide margin, because Olmert and all of the leadership candidates support it. While it does not block Olmert from running in the race, it does not make it easier for him to run, either. Olmert's loyalists in the party had considered raising additional proposals to help him stay in power. Two ideas, now ruled out by Wednesday's agreement, were to hold a second primary before the next general election to select the party's candidate for prime minister or to stipulate that the current race would select Olmert's deputy, who would automatically be promoted should Olmert have to resign due to one of the criminal investigations against him. "Every proposal raised will have the approval of all the candidates, so there won't be any room for political tricks," a Kadima official said. The proposal that will be voted on also received the endorsement of Labor Party secretary-general Eitan Cabel. The Labor executive committee will meet in Tel Aviv before the Kadima council gets together. Labor chairman Ehud Barak is expected to address the situation in Kadima at his party's meeting. Ben Sales contributed to this report.