The field of leadership candidates in the May 28 Labor Party leadership race became clearer on Monday when National Infrastructures Minister Binyamin Ben-Eliezer revealed that former prime minister Ehud Barak told him he was running. Ben-Eliezer told The Jerusalem Post that he has been meeting with all the candidates for the Labor leadership, including Barak. He said that he asked Barak whether he was running and he gave a clear answer in the affirmative. Sources close to Barak said he would announce his decision within a week but that he is currently abroad. Seeking the Labor leadership would require Barak to cancel many business opportunities abroad and devote himself full-time to the race. Asked whether he was registering people on Barak's behalf in the membership drive, Ben-Eliezer said he had thousands of loyalists who were returning to Labor to support him, even though he is not running, so he could remain a force in the party. But sources close to Ben-Eliezer said that Barak was the most likely candidate for the Ben-Eliezer backers to support. Barak is said to have a difficult time conducting a membership drive, but Ben-Eliezer's support would significantly increase his chance of returning to the Labor leadership. Two other prospective candidates, MKs Avishay Braverman and Matan Vilna'i, said Monday that they had not yet decided whether to run. They both said they would announce their decision about whether to run in upcoming days. Although it appeared at one point that there could be as many as nine Labor candidates, if Braverman and Vilna'i do not run, there would be only five: Incumbent Amir Peretz, the leading candidate in the polls Ami Ayalon, Barak, and MKs Ophir Paz-Pines and Danny Yatom. Meanwhile, Labor faction chairman Yoram Marciano called upon Prime Minister Ehud Olmert to fire Minister-without-Portfolio Avigdor Lieberman after his Israel Beiteinu party did not support the government in a no-confidence motion.