The chances of a united Center-Left list running in January’s election seemed as unclear as ever on Saturday night, with Labor leader Shelly Yacimovich and Yesh Atid chairman Yair Lapid hinting they would be willing to run with former Kadima leader Tzipi Livni.Sources close to Livni, however, said that the former foreign minister was unlikely to make a political comeback if she would not a candidate for prime minister.Yesh Atid refused to confirm the reports, but in interviews on Thursday night, Lapid said he would not run with Yacimovich, insisting he was not leading a left-wing party. He dodged questions about Livni.Yacimovich also said on Saturday that she found it “unacceptable” that former prime minister Ehud Olmert may return to public life, because of his legal troubles.A source close to Olmert reiterated that the former prime minister still had not made a decision, but was skeptical about a comeback.He added that the results of the November 6 US presidential election could influence Olmert’s choice. If Republican nominee Mitt Romney won, Prime Minister Binyamin Netanyahu would get a boost, but if President Barack Obama was reelected, the source posited, Olmert would be more likely to run for the 19th Knesset.MK Amir Peretz (Labor) spoke to the leaders of the parties in the Center and on the Left this weekend – Yacimovich, Lapid, Kadima chairman Shaul Mofaz and Meretz chairwoman Zehava Galon – about his plan to take down Netanyahu.The “Peretz Plan” is for the four parties – Labor, Yesh Atid, Kadima and Meretz – to commit to, after the election, recommending to President Shimon Peres that whichever of them gets the most votes, should be the next prime minister.Peretz posited that the left-wing and centrist parties were likely to get more seats in the next Knesset if they ran separately, and not as a bloc.“We need to cooperate, because Netanyahu and Liberman could bring Israel five more lost, frozen years in social and diplomatic areas, and the erosion of diplomatic values,” Peretz said. “This is the time for national responsibility.We must do everything to create a common denominator that will bring agreements and better the country's future.”“Camp Sucker,” the protest movement calling for universal IDF or civilian service, launched a campaign on Saturday calling for Olmert, Livni, Yacimovich, Lapid and former IDF chief of staff Gabi Ashkenazi – who has discussed joining an Olmert- or Livniled list – to run together.“Give up your ego, don’t give up on the country,” Camp Sucker leaders Boaz Nol and Idan Miller said.“Netanyahu and Liberman lied to us when they promised a law for equality in the burden of service in the 18th Knesset. We need to build an alternative.”Meanwhile, Yacimovich insisted that she would not join a coalition that included Foreign Minister and Yisrael Beytenu chairman Avigdor Liberman, saying in an interview with Channel 2 the chances it would happen were “almost imaginary,” but that she would sit with almost any party – except for National Union MK Michael Ben-Ari – that would allow a “significant, structural change.”Yacimovich slammed the idea of separating the political field into right- and left-wing blocs based on diplomatic plans, saying many Likud voters were considering voting for Labor following the Likud’s electoral union with Yisrael Beytenu.The Labor chairwoman also announced on Saturday night that former IDF spokesman, television reporter and Kadima MK Nachman Shai would be running in her party’s primary.Shai said he decided to move to Labor because of a need to “unite forces,” calling the party “a sharp and clear alternative to the Netanyahu- Liberman party. This is a social, economic and diplomatic path that ensures the future of the State of Israel as a Jewish and democratic country.”Also on Saturday night, following several days of media speculation and differing predictions about the top spots in Yesh Atid’s list, the party confirmed that Rabbi Shai Piron would be its No. 2 candidate.Piron is the head of Petah Tikva Yeshivas, which includes a hesder yeshiva and a high school, and directorgeneral of Hakol Hinuch, the Movement for the Advancement of Education in Israel, and a founder of the religious- Zionist organization Tzohar.Livni herself told Labor Women leader Leah Fadida on Saturday afternoon that she had yet to decide whether she would return to politics. Fadida, a candidate in the Labor primary, briefly met with Livni on Saturday night, asking her to join the party.When asked about Livni, Yacimovich said she was being discreet about the “endless list of very good people” she had met in connection to the election.“Livni has a place in the political field,” Yacimovich added. “She is one of the only people who bring [seats in the Knesset] with them.”Sources indicated on Friday that Lapid was prepared to unite with Livni in light of the Likud-Yisrael Beytenu unity deal, but any joint effort would be highly conditional as he would only consider such a deal if he was still at the top of the joint list.