Former general Amiram Levine, a close political ally of Labor leadership candidate Ami Ayalon, fiercely attacked his main rival in the race, former prime minister Ehud Barak, in a weekend interview with Ma'ariv. Levine accused Barak of having a "mental problem" and a "screwed-up brain." He said the unilateral withdrawal from Lebanon that Barak initiated as prime minister was "a catastrophe that convinced Hizbullah that it could defeat us and expel us." Ayalon's campaign said Levine was speaking for himself and he was not sent to be interviewed by the campaign. But Barak's associates accused Ayalon of playing dirty and Levine of acting out of bitterness to Barak because he did not appoint him Mossad chief when he was prime minister. "We don't intend to conduct a negative campaign," a Barak spokesman said. "When Barak speaks, he points out his opponents' lack of experience, but he will never call any of them insane." Ayalon's campaign strategist Yuval Porat of the Spin agency said Ayalon's strategy ahead of the May 28 primary would be to tell Labor members that "only new leadership can win the next general election and old leadership cannot." Barak held a meeting with his supporters in the Labor faction on Friday and they decided that for the rest of the campaign he would use two slogans: "Only Barak can beat Bibi" and "Uniting behind Barak and winning." The slogans are intended to emphasize that Barak is the most electable prime ministerial candidate and that Labor members should not waste votes on Defense Minister Amir Peretz and MK Ophir Paz-Pines, who are trailing behind Ayalon and Barak in the race.