Front-running Labor leadership candidate Ami Ayalon tried in vain to persuade MK Danny Yatom to quit the contest when they met over lunch at a Tel Aviv restaurant on Thursday. With all five candidates insisting on remaining in the May 28 primary, a runoff will likely have to be held on June 11 to decide who will be Labor leader. Both Ayalon and former prime minister Ehud Barak have tried to attract the support of Yatom, a former Barak aide who is running last in the polls. But Yatom has vowed to remain in the race against all odds. "I am not joining Ami Ayalon or any other candidate," Yatom said after the meeting. "We will meet at the polls on May 28." Yatom's spokesman said he had not even begun to consider whom he might support in a runoff between Ayalon and Barak. He said Ayalon and Yatom merely dealt with the issue of how to keep Labor united after the race no matter who emerges victorious. "He is running because, even though no one understands it, he genuinely believes that he is the most fitting candidate in the race," Yatom's spokesman said. In recent days, all the candidates have been sending out press releases with the names of former politicians and security men who have endorsed them but are not expected to change the minds of any voters. The names have included former police inspector-general Assaf Hefetz (Barak), former MK Michael Bar-Zohar (Ayalon) and former JNF head Yehiel Leket (Ophir Paz-Pines). The Labor faction will meet in a special session next week to discuss the Saudi peace plan at the request of Ayalon. "The Arab countries have announced that they have made a strategic decision to make peace with Israel and condemn terror," Ayalon said. "Such a dramatic development requires deep deliberation on our part."