Shas became the second party to join Prime Minister-designate Binyamin Netanyahu's government Sunday night, signing a deal just after midnight. Shas chairman Eli Yishai will take the Interior Ministry portfolio as part of the agreement. The deal also guarantees Shas the Construction and Housing, and Religious Services portfolios. The party gave up its attempt to appoint a minister for haredi education and instead will receive a minister-without-portfolio in the Prime Minister's Office. Netanyahu now has a coalition of 53 MKs in hand from Likud, Israel Beiteinu and Shas. Coalition talks will continue on Monday with Labor, United Torah Judaism and Habayit Hayehudi. The party will also have a deputy minister in the Finance Ministry. Earlier on Sunday, Prime Minister Ehud Olmert lashed out during a cabinet meeting at the possible political alliance between Netanyahu and Labor chairman Ehud Barak, saying that anyone not working off the premise of two states for two peoples is "deluding themselves and the public." Olmert said that if the new government did not actively pursue the formation of a Palestinian state, it would lead to international isolation and an unprecedented diplomatic crisis that could cause Israel "irreparable damage." He asked how it would be possible to work productively with the international community on other issues, such as Iran, and not accept the international consensus of the need for a two-state solution. "A government whose basis is not saying 'two states for two peoples'... will find itself bearing responsibility for a great calamity," Olmert told the cabinet. "History will not forgive those who know the truth in their hearts but ignore it for extraneous considerations that have nothing to do with the good of the country." When Barak entered the room, Olmert said he was not referring to anyone personally. But it was clear to the ministers that he had been talking about Barak, whom he has loathed since the Labor chairman forced his resignation from the premiership last year. The Likud expressed outrage at Olmert for interfering with Netanyahu's efforts to form a national-unity government with Labor by the April 5 deadline. Netanyahu's associates expressed confidence that the coalition would be finalized next week. "Olmert's hatred for Barak has made him go insane," a senior Likud source said. "He cares more about preventing Barak from remaining defense minister than about what is good for the country, which is a national-unity government as soon as possible." Barak's office accused Olmert of a "pathetic attempt to harm the defense minister in any way possible and at any price" and called on Olmert to "leave quietly." Sources close to Barak also expressed anger at Olmert for trying to persuade Welfare and Social Services Minister Isaac Herzog not to support Labor joining the government. Herzog's office confirmed a report by Channel 1's Ayala Hasson that Olmert had spoken to the minister outside the cabinet meeting and told him not to back Barak's effort to bring Labor into Netanyahu's government. Herzog, who is Barak's No. 2 in Labor, remains undecided, and his decision is key ahead of Tuesday's decisive party convention. In a lengthy meeting with Barak on Sunday, Herzog told him that since February's election, he had leaned toward entering the opposition. He issued a series of demands on socioeconomic and diplomatic issues and requested in-depth answers in the coalition agreement that Labor and Likud would draft. Herzog's associates would not reveal any of the conditions, but stressed that they had nothing to do with cabinet portfolios. They denied a Channel 10 report that he had asked for Labor's second-best portfolio. The report said that to satisfy Herzog, the Labor portion of the former Labor and Social Affairs portfolio could be returned to his present portfolio from its current home in the Industry, Trade and Labor Ministry. Barak appointed a coalition negotiating team on Sunday composed of Histadrut chief Ofer Eini, Agriculture Minister Shalom Simhon and attorney Alon Gellert, who served as chief legal adviser to the Prime Minister's Office under Barak. Barak met with the team on Sunday night and briefed them about agreements he had already reached with Netanyahu in their recent closed conversations. The team is expected to meet with the Likud's negotiators on Monday morning. MKs in Labor who oppose joining the government lashed out at Barak for forming a negotiating team before the central committee meeting. "A Labor chairman has never appointed a negotiating team without permission from his party's institutions," the MKs said in a joint statement. "This is a violation of democratic norms and an attempt to force a fait accompli on the convention." Sources close to Barak confirmed that the aim of negotiating the principles of a deal with Likud before Tuesday was to avoid having to hold two separate committee meetings, one to authorize beginning negotiations and another to approve a coalition deal. The draft will be presented at the convention. Barak attempted on Sunday to end speculation that he would leave Labor and enter Netanyahu's government as a professional appointment if he lost Tuesday's vote. According to Israel Radio, Netanyahu told Labor MKs he was not interested in appointing Barak if he did not bring several Labor MKs with him. "You should direct the question to those who threatened to split more than once and not to me," Barak said when asked whether he'd stay in Labor if he lost the vote. "The answer is positive and obvious." Simhon, who is close to Barak, went further, telling Israel Radio, "There is no chance in the world that Barak will split from Labor. There is no danger, even if his view isn't accepted. Barak has no intention of splitting." Herb Keinon and Jpost.com staff contributed to this report.