Results of the Israeli Labor party primaries released early Tuesday morning showed that neither of the two leading candidates, Ehud Barak and Ami Ayalon, received the 40 percent threshold to win an outright victory, leaving the future party-head to be decided in a run-off in June.

According to Israeli media, with ballots from 99.7 percent of voting stations tallied, the results awarded former Prime Minister Ehud Barak the victory of Monday's ballot with 35.7 percent, while the former head of Shin Bet (Israel Security Agency) Ami Ayalon with 30.7 percent.

But neither of the two received the 40 percent threshold to win in a single round of balloting, which means the race between Barakand Ayalon will not end until a run-off is held next month.

Current Labor Chairman and Defense Minister Amir Peretz gained the support of 22.3 percent of the voters in the campaign, and the other two candidates garnered less than 10 percent of the votes.

Monday's ballot opened at 8:30 a.m (0530GMT) and closed at 9:00p.m. (1800GMT). Up to 65.5 percent of the 103,498 eligible voters turned out to vote for their preferred candidate.

With 19 seats in the Israeli Knesset (parliament), Labor is the most important coalition partner of Kadima.

However, in the wake of a highly critical government report on Israeli leaders' performance during last summer's conflict in Lebanon, both Barak and Ayalon have pledged to seek change of the head of government, if they are elected to lead the party.

Ayalon said that he would lead the party out of the current coalition government presided by Prime Minister Ehud Olmert, if Olmert's Kadima Party didn't choose a new leader.

Barak, meanwhile, has said that he would serve temporarily in the Olmert government, but would work within the parliament to topple the Israeli leader and call for early elections.

If Labor withdrew from the current coalition government, Olmert would have to seek replacements amongst the Knesset factions to keep the coalition in place.