Israeli Prime Minister Ariel Sharon's bitter rival, Benjamin Netanyahu, launched a bid on Tuesday to topple him as Likud party leader in a power struggle sparked by the evacuation of Gaza settlers.
Likud polls show ex-finance minister Netanyahu would rout Sharon in a primary if it were held soon, stirring speculation Sharon may break away from rightists and forge a new centrist party to run in an election due before November 2006.
Likud's hard-line Central Committee is expected to stage a primary as early as November, a move that could reshuffle Israel's political deck and lead to an early general election. Sharon, 77, is aiming for a third term.
Netanyahu, 55, prime minister in 1996-99, resigned in protest this month over Sharon's evacuation of all 21 Jewish settlements from Gaza and four of 120 in the West Bank under a US-backed plan to "disengage" from conflict with Palestinians.
Netanyahu is the hero of hardline nationalists in a split Likud, saying the pullout will imperil Israel by turning Gaza into an "independent terrorist base" rather than a model for Palestinian statehood as US-led peace mediators hope.
"Ariel Sharon has gone a different way, the way of the left. Likud needs leadership that will repair the damage ... to our state. I believe I can do this and will stand for the Likud leadership and premiership," Netanyahu told a news conference.
The looming Likud showdown will be a culture clash as well.
It pits Sharon, a stout former general known for hard-nosed leadership and distaste for messy debate, against Netanyahu, a US-educated master of the soundbite who revived Israel's economy, although he is seen by some as prone to posturing.
While many in Likud see Netanyahu as truer to party principles than Sharon, cross-party polls have consistently shown Sharon to be the most popular and respected Israeli leader and more likely to win the next election at the party's helm.
Most Israelis favour Sharon's security strategy, which entails ceding more West Bank settlements as part of any final peace deal with Palestinians but keeping the biggest settler blocs in the territory he sees as strategically vital.
Sharon stole a march on Netanyahu's announcement by lambasting his rightist rival on Monday as someone who quickly "panics and loses his cool" under pressure and calling him unfit to lead Israel in any peace process with Palestinians.
Netanyahu hit back on Tuesday: "You can judge by yourselves which one of us is under pressure, reacting to pressure."
"What the public wants to know is when will it get a prime minister who stops putting wind in the sails of terrorists and begins to demand things in return for concessions."
Sharon says his plan extracted isolated settlers from land Israel would not keep under any peace deal and won US acquiescence in a permanent Israeli hold on major West Bank settlements within the Israeli consensus.
The primary vote would mark the first time an Israeli party has tried to topple a serving prime minister as its chairman.
Maariv newspaper columnist Ben Caspit said "bad blood was boiling" between Sharon and Netanyahu and predicted "one of the fiercest and dirtiest political battles Israel has ever known".
Sharon hopes for a boost from the World Summit at the United Nations in mid-September where he is expected to reap accolades for the first removal of Israeli settlements from territory where Palestinians want to create their own state.