Prime Minister-designate Binyamin Netanyahu remains confident that he can form a government without asking President Shimon Peres for a two-week extension, despite problems in negotiations with Shas, sources close to the Likud leader said Tuesday. The sources based their optimism on a legal opinion they received from Beit Hanassi's legal adviser, Udit Corinaldi, saying that the deadline for forming a government is not Friday at 3 p.m., as previously thought, but Sunday at the same time. Corinaldi's ruling is based on clauses in the Basic Law: The Government that indicate that the day on which the president designates a Knesset member to form a government is not counted in the 28 days the candidate is given, and if the final day of the 28 falls on Shabbat, that day is not counted either. Other legal experts interpreted the law in a stricter manner and said Netanyahu's deadline was actually midnight on Thursday night. Sources connected to Attorney-General Menahem Mazuz said he was looking into the matter and would advise Corinaldi before a final decision was made on when Netanyahu's deadline. Netanyahu looked like he could use all the time he could get after no deal was reached in a meeting with Shas chairman Eli Yishai on Tuesday morning at the Knesset. The two men met again late Tuesday night, but they were not expected to finalize a deal until Wednesday at the earliest. The problems with Shas centered on issues related to real estate reforms to alleviate the housing shortage in the haredi sector, budgets for yeshivas, and the question of whether Shas would be given a minister in charge of haredi education. The Education Ministry is sensitive for the head of the Likud's negotiating team, MK Gideon Sa'ar, because he has been promised the portfolio. The slow pace of talks with Israel Beiteinu and Shas angered the other three parties that want to join the coalition, United Torah Judaism, Habayit Hayehudi and the National Union, who have been neglected by the Likud negotiating team while it works on deals with the two larger parties. Israel Beiteinu leader Avigdor Lieberman, who finalized his deal with the Likud early Monday, called upon right-wing parties to "behave responsibly and flexibly" and join the government as soon as possible. He warned them not to repeat their mistakes of toppling governments led by Likud prime ministers Yitzhak Shamir and Netanyahu in 1992 and 1999 that led to the election of left-wing governments. "It is important to learn lessons from the not-too-distant history," Lieberman said at the start of a meeting of his party's secretariat in Jerusalem. "There are many reasons to expedite the negotiations, including economic and security issues and the Gilad Schalit episode. "Because of this we have to set aside disputes. The sooner the government is formed, the better it is for Israel." Lieberman expressed hope that the coalition negotiations would end on Friday and the new government would be sworn in on Monday. Netanyahu is not expected to allocate portfolios to ministers inside his party until the last minute. The only Likud MKs who know their fate are Sa'ar and Moshe Ya'alon, who is expected to be appointed defense minister. According to the latest round of speculation inside the Likud, MK Yuval Steinitz will be a minister-without-portfolio in the Finance Ministry, MK Dan Meridor minister of strategic affairs, MK Yuli Edelstein the minister-without-portfolio who acts as the liaison between the government and the Knesset, and MK Ayoub Kara minister of minority affairs. Netanyahu met with 25 Druse activists at the Knesset on Monday and told them he wanted to see Kara in his cabinet. Assuming the Welfare/Social Affairs, Science and Agriculture portfolios are given to United Torah Judaism, Habayit Hayehudi and the National Union, that would leave five portfolios available for Likud MKs: Transportation, Health, Environment, Communications and Industry, Trade and Labor. The six MKs competing for those ministries are Silvan Shalom, Bennie Begin, Yisrael Katz, Moshe Kahlon, Gilad Erdan and Limor Livnat. If Shalom decides not to enter the government as he has hinted, Netanyahu would have just the right amount of ministries for his ministers in waiting. Rebecca Anna Stoil contributed to this report.