Israel's former defence minister Shaul Mofaz roundly defeated his rival for the leadership of the country's opposition party Kadima, taking nearly two-thirds of the vote, the party said on Wednesday.
In a statement, Kadima said Mofaz had taken 61.77 percent of the primary votes to oust his rival, incumbent faction leader Tzipi Livni.
Livni, a former foreign minister and one of the first to join the Kadima party when it was formed in 2005, took 37.23 percent of the vote, the statement said.
Mofaz was pronounced the winner in the early hours of Wednesday morning, ending Livni's three-and-half-year reign as party leader, and raising questions about her future and that of the opposition faction.
Turnout at the primary was low, with 41 percent of Kadima's 95,000 registered members casting their ballots on Tuesday.
Livni has been criticised for failing to clearly define Kadima, or provide concrete differences between the faction and other parties, including Prime Minister Benjamin Netanyahu's Likud.
Kadima was founded in November 2005 by former prime minister Ariel Sharon who left his political home in the Likud party after his controversial decision to pull all settlers and troops out of the Gaza Strip.
It is currently the largest party in parliament, holding 28 seats in the 120-seat Knesset, but a series of recent polls suggest the faction is likely to see that number halved in the next elections.
Those polls are officially tabled for October 2013, but rumours of an early election are rife, with observers speculating they could take place before the end of this year.
Tuesday's primary vote pitted Livni against her deputy Mofaz, an Iranian-born former army chief-of-staff who once held the defence portfolio.
Both are former members of the Likud party and have been bitter rivals since a tight leadership race in September 2008 which saw Livni win by just 413 votes to replace scandal-plagued premier Ehud Olmert as party head.
Mofaz, who has a rich history of military experience, has spent only 10 years in politics, although he currently heads the powerful parliamentary committee on foreign affairs and defence.
During the campaign, Livni emphasised the differences between herself and Mofaz, saying he was willing to join a coalition with Netanyahu— something she declined to do in 2009.
Commentators said it seemed possible that Kadima would split in the wake of the primary, with Livni either leading supporters to a new party or even choosing to retire from politics altogether.
But after Mofaz's victory was announced early Wednesday, he called on his rival to remain within Kadima.
"I call on Tzipi Livni to join us in this battle... Tzipi, your place is with us," he said in his victory speech, pledging to lead Kadima to victory over Netanyahu in the next elections.
Livni phoned Mofaz to congratulate him, but did not offer public support for the party's new leader.
"These are the results. I thank all the members of Kadima who gave me their confidence and their support," she told supporters.