Negotiations on forming Acting Prime Minister Ehud Olmert's new government will not begin until Sunday, but the seeds of the first rebellion within the coalition already sprouted on Thursday, when officials in Avigdor Lieberman's Israel Beiteinu party vowed to fight Olmert's West Bank convergence plan from inside the government. In his acceptance speech after President Moshe Katsav formally invited him to form the government, Olmert said that all his potential coalition partners were aware that the convergence plan would be "the basis of the government's operations," even though the plan would not be specifically mentioned in the coalition guidelines. Olmert's associates said that not using the word convergence but making it clear that this would be the government's course of action was Olmert's way to enable both Labor and Israel Beiteinu to join the coalition. He decided to build an 84-MK coalition of Kadima, Labor, Shas, Israel Beiteinu, the Gil Pensioners Party and United Torah Judaism, so that neither Labor on the left nor Israel Beiteinu on the right could topple the government. But Israel Beiteinu officials reshuffled the cards on Thursday when they revealed that one of their reasons for the party joining the government was to try to prevent the unilateral withdrawal from happening. "The way to have an impact is to join the coalition," said MK Yuri Shtern, the party's No. 2. "We are against unilateral withdrawals and we will try to work against them. In the coalition talks, Olmert will say what he believes in, we will say what we believe in and then we will see what is possible." Labor chairman Amir Peretz demanded on Thursday that the word convergence be added to the coalition guidelines to keep Lieberman out of the government. Labor officials said they hoped they could convince Olmert to include Meretz in the coalition instead. "We will lobby hard to prevent Israel Beiteinu from joining the coalition," Labor secretary-general Eitan Cabel said. "Kadima should agree to keep Lieberman out because we gave up our effort to form our own coalition." The coalition talks will kick off Sunday morning at Ramat Gan's Kfar Hamaccabiah Hotel with talks between Kadima and Labor. Former justice minister David Liba'i will square off in the meeting against the Kadima coalition team of Olmert aides Yoram Turbowitz, Eyal Arad, Ovad Yehezkel and Hagai Elias and lawyers Ram Caspi and Eitan Haberman. Talks will then be held with the rest of the parties in order of size, starting with Shas, Likud, Israel Beiteinu, Gil, UTJ and Meretz. Kadima officials said the first days of the talks would be devoted to reaching a consensus on the coalition's guidelines on diplomatic and socioeconomic issues, and portfolios would only be dealt with after Pessah. "No party will be able to get everything it wanted," Arad said. "A coalition is about sharing power." Following Sunday's talks, the heads of Kadima, Labor and the Likud will all host pre-Pessah toasts for their party activists. Olmert's toast will be his first appearance at a Kadima political gathering since his infamous Rishon Lezion speech three weeks before the election in which he said that Kadima already had the race won.