As first reported by The Jerusalem Post, Shimon Peres has decided to leave the Labor Party and join Ariel Sharon's next government, a senior Sharon adviser said Tuesday. The adviser, Lior Horev, said Peres will not join Sharon's new party, Kadima. "Tomorrow, he (Peres) will have a news conference," Horev said. "He will leave the Labor Party ... and will join the Sharon government and deal with the (development of) Galilee and the Negev," Horev said. Sharon's associates said late Monday night that Peres had finalized his decision to leave Labor. In addition to Peres, Labor suffered another blow when, following a meeting with Sharon at the Prime Minister's Office in Jerusalem, Labor MK Dalia Itzik announced at 11 p.m. on Monday that she was leaving Labor for Sharon's Kadima party. Despite the departure of Peres and Itzik, Labor could be comforted by the announcement of well-known Israeli journalist Sheli Yehimovitch, who declared on Tuesday morning that she was quitting Channel 2 and joining Labor under Peretz. Yehimovitch is known for her adament socio-economic agenda. Sharon's associates, meanwhile, said that Itzik was part of a deal worked out with Peres, who insisted that Sharon find room on the Kadima list for his closest political ally. "Sharon is willing to pay the price of a slot on Kadima's list for Dalia Itzik to bring about the departure of Shimon Peres from the Labor Party," a Sharon associate said. When Peres returns from a trip to Spain on Wednesday evening, the veteran politician will quit party politics and announce that he has accepted an offer from Sharon to become a senior minister in charge of peace talks with Palestinians and developing the Negev and Galilee. Peres gave a hint about his political future when he told reporters in Barcelona on Monday night that "My goal is to make peace and it doesn't matter with which party." "We have no doubt that the two most experienced people in Israeli politics will continue to lead the country," a Sharon associate said. "This is a blow for Labor chairman Amir Peretz, whose inexperience will be even more blatant now." When Peretz was elected Labor leader three weeks ago, he pleaded with Peres in his victory to speech to stay in Labor. "Shimon, I need you," he said. But Peres never forgave Peretz for breaking a promise not to run against him for the Labor leadership, which he made after Peres worked hard to bring Peretz back into Labor. Since his loss to Peretz, Peres has taken a break from politics. Itzik met with Peretz earlier Monday for more than an hour. Both sides described the meeting as cordial, but Itzik had apparently made up her mind going into the meeting that she would join Kadima later that day. Sharon and Itzik were considered close during Sharon's first term as prime minister, but their relationship deteriorated during coalition talks before Labor joined the government nine months ago. Itzik angered Sharon when she suggested that he wanted the Likud to maintain the Internal Security portfolio because he and his sons were being investigated. Meanwhile, Education Minister Limor Livnat threatened to fire the Director-General of the Education Ministry, Ronit Tirosh, if Tirosh did not deny rumors that she is joining Ariel Sharon's Kadima Party. Sharon associates reportedly contacted Tirosh recently, and proposed that she join Kadima.