Israeli Prime Minister Benjamin Netanyahu has claimed victory in the primary of his rightwing Likud party over his sole rival, the hardline settler Moshe Feiglin.
"I thank you for the confidence and the renewed support that you have given me," Netanyahu told a party gathering before the official results were announced.
Sources close to the premier said he may have taken as much as 80 percent of the vote -- up from 75 percent in the last primary in August 2007. Feiglin had captured 24 percent of the 2007 vote.
Final results were expected later Wednesday.
Media put turnout at about 48 percent of the 125,000 party members registered to vote. There were 150 stations across the country, including in the West Bank, where Feiglin cast his ballot.
In an earlier statement, Netanyahu congratulated his party, saying: "Today, the real Likud won. We proved that our strength is our unity. We will continue to lead the country in a responsible way... for the good of all Israelis."
Netanyahu's surprise decision in December to move the vote forward sparked speculation about whether he would also bring forward general elections scheduled to be held around November 2013.
Under the party's constitution, leadership primaries must be held up to six months before general elections.
Netanyahu said the move was a way to save money, explaining that holding the primary on the same day as the party's convention would save millions of Israeli shekels (hundreds of thousands of dollars).
But commentators characterised it as an attempt to capitalise on his domestic popularity, with polls placing him far ahead of Feiglin as well as future competitors for the prime minister's office.
His Likud party also remains well ahead of the opposition, according to recent opinion polls.
The prime minister and his wife Sarah were first in line to cast their ballots in Jerusalem as polls opened at 0800 GMT.
In Jerusalem, home to Likud's biggest branch and a Feiglin stronghold, rival tents set up outside a polling station blared music intended to entice voters. Feiglin's tent attracted the largest crowd, most of them religious Jews.
A religious Jew who lives with his wife and five children in the West Bank settlement of Karnei Shomron, Feiglin is known for his hardline positions, particularly on the Palestinians and Israel's Arab minority.
He opposed the Oslo peace accords and has said that Palestinians and Arab Israelis should be paid to move to Arab countries.
He hoped to capitalise on settlers' anger at Netanyahu over his plan to comply with a High Court ruling ordering the relocation of a West Bank settlement outpost.
Feiglin has also sought to encourage activists who do not vote for Likud in general elections to become party members in order to influence the primaries, according to political commentator Hanan Crystal.
"Thousands of settlers who don't vote for Likud in the legislative elections, choosing instead groups that are more to the right, have registered with Likud so as to influence the party line," Crystal told AFP.
"They represent about nine percent of its members. But their strength is greater than that because they form a bloc that will vote massively against other members of Likud," he added.
Crystal said a strong showing for Feiglin could push Likud to the right because its members would fear angering his voting bloc as the party puts together its list of candidates for the general election.