JERUSALEM, Jan. 8 (JTA) — Ehud Barak, the frontrunner for the Labor Party leadership, has won important support for his proposal on how the party’s chairman should be chosen. His proposal was approved Wednesday at a meeting of the Labor Party Congress, which voted down another motion submitted by Haim Ramon, another contender for the party leadership. Ramon told the session that he would likely not run against Barak when the leadership contest is held in June. Under Barak’s proposal, only paid-up party members would be entitled to vote for the leader in the June primaries. Ramon had wanted open primaries in which any Israeli citizen who was not a registered member of another political party could vote. The candidates for the Labor Party leadership who have formally thrown their hats into the ring are Barak, a former Israel Defense Force chief of staff who served as foreign minister in the 1995-1996 government of Prime Minister Shimon Peres; Yossi Beilin, a longtime Peres acolyte who served as minister without portfolio in the previous government; and Ephraim Sneh, a doctor and former brigadier general who was minister of health in the Peres government. First-term Labor Knesset member Shlomo Ben-Ami, a history professor and former ambassador to Spain, is also considering running. Peres has said he would not seek the party leadership, but has left open the possibility that he would serve in a leading role if a national unity government were formed this year. At Wednesday’s session of the Labor Party Congress, Barak maintained that the result of the primary would be unaffected by the voting system chosen. Ramon, however, claimed that a “closed primary” reserved for party members would be heavily influenced by the 30,000 to 40,000 party machine officials. He said an open primary would test candidates’ strength among the broader public — and thereby better approximate the fight against Netanyahu for the premiership in the year 2000. Ramon was jeered as he strode to the rostrum, where he delivered a withering attack on Barak. Ramon portrayed Barak as a captive of the machine politicians who, he said, were the most conservative and reactionary element in Labor.