Sources close to Kadima leader Tzipi Livni and Likud chairman Binyamin Netanyahu expressed hope on Sunday that a "responsible adult" would intervene in their efforts to build a new government after the two sides grew further apart. Both Netanyahu and Livni called for the formation of a national unity government during the campaign, but they have been sparring over who should head it since last Tuesday's election, when Livni's Kadima won one more seat than Netanyahu's Likud but the Right bloc beat the Left by 10 mandates. Names mentioned as possible saviors to break the deadlock included President Shimon Peres, Israel Beiteinu leader Avigdor Lieberman and even US President Barack Obama, all of whom reportedly back the formation of a unity government. Peres is expected to formally initiate efforts to form a new coalition after the final results of last Tuesday's election are published in the government registry no later than Wednesday. He will meet with all the factions to help determine whom they think he should entrust with forming a coalition, which he could do as early as Friday. But it remains unclear to what extent Peres will push for a unity government and interfere in decisions about what coalition should be formed. Lieberman is set to return from a vacation in Minsk on Wednesday morning, knowing that as the head of the third largest party, his recommendation to Peres holds considerable sway. Sources close to Lieberman said he would likely recommend to the president that Peres ask him to form a government and then he would offer to help broker a deal between Netanyahu and Livni. But his role as a mediator would be limited, because he is an interested party. The British Daily Telegraph newspaper quoted sources in Washington on Saturday who have discussed the Israeli political situation with members of Obama's team. They said Obama was prepared to play a role behind the scenes to ensure that a unity government could be formed. While the Obama administration insists publicly that it will work with any Israeli government, according to the report, Obama's advisers believe he could wield his political capital to help bring about a unity government if Netanyahu asked him to pressure Livni to take her party into a government under his leadership. But that scenario is the least likely, because Obama would not want to be seen as interfering in the politics of a foreign country. The impasse between Livni and Netanyahu intensified on Sunday when Livni said she would not join a government under his leadership and hinted that the least she would accept was a rotation whereby they would each serve as prime minister for two years. But Netanyahu has made clear that to bring Kadima into a government led by him, he would offer anything except for the premiership itself. When asked whether Netanyahu preferred a rotation with Livni or the formation of a narrow, rightist government, a source close to him said the Likud leader was convinced that that once he succeeded in forming a government with parties on the Right, Kadima would decide to join, too. But Livni seemed to rule that out Sunday when she told Prime Minister Ehud Olmert in a note she wrote him in the cabinet meeting that was revealed by Channel 2's Web site the she "has no intention of sitting in a unity government led by Netanyahu." Later, in a Kadima faction meeting at the Knesset, Livni claimed that she had won the race and therefore should be asked to form the government. She said that if Netanyahu were asked to form the government, she would prefer the opposition. "You don't have to be a math genius to know that 28 seats is more than 27," Livni told her MKs. "The public decided between Tzipi and Bibi. There was no ballot with the words bloc or camp on it." Livni accused Netanyahu of preferring to reach a deal with "extremists" on the Right rather than form a government with Kadima. She vowed that Kadima would resist temptation to join a Netanyahu-led government in return for key portfolios. "We will continue serving the public, whether it is as the public wants, in forming the government, or in the opposition, or wherever we find ourselves," Livni said. "Even if I will not head the government, we must fight for what is right." Livni's associates said that when she spoke about the possibility of a government under her leadership, she was also referring to the option of a rotation in the Prime Minister's Office. They predicted that Livni's argument that she should form the government would gain credence if Lieberman did not recommend to Peres that Netanyahu be entrusted with building a coalition. "If neither can form a government, then she can come with the moral claim that 30,000 more people preferred her over Netanyahu," a source close to Livni said. "The results of the election indicated that what the public wants is a right-wing government led by Tzipi." The Kadima faction backed Livni's resistance to joining a unity government under Netanyahu's leadership and left open the possibility of a rotation. "Bibi said during the campaign that people should vote for him and not his bloc, but now he is saying that people should look at the achievement of his bloc and not him," Finance Minister Ronnie Bar-On said. "Livni should be prime minister and if not, we say, no thank you. It's either Tzipi at the head of the government or of the opposition. We will run the opposition with the same determination that we ran the country." The only other coalition that could be formed besides a unity government would be a narrow, rightist government led by Netanyahu. The main problem with forming such a coalition is the dispute between Lieberman and Shas, whose mentor, Rabbi Ovadia Yosef, called Lieberman "a devil" during the campaign. Likud MK Ze'ev Elkin recently began mediating between Shas and Israel Beiteinu, especially on the two most critical issues for Lieberman, reforms in conversion and the registration of civil unions. But officials involved in the talks said they had just begun and they were still far from reaching a solution.