Israelis head to the ballot box Tuesday with polls suggesting they're weary of incumbent Prime Minister Benjamin Netanyahu, yet wary of choosing a new leader amid mounting security threats and deadlocked peacemaking with the Palestinians.

Surveys indicate Tuesday's election is too close to call. Most show Netanyahu's Likud party trailing opposition leader Isaac Herzog's Zionist Union by three or four of parliament's 120 seats, with both falling far short of a majority. While polls show Netanyahu better able to build a coalition with smaller factions that share his reluctance to cede land to the Palestinians, the shift of a few seats could turn the tide in Herzog's favor, or compel the two to form a unity government.

The election comes as Israel is grappling with stalled negotiations with the Palestinians, rising Islamic militancy on its borders, Iran's nuclear program and growing friction with the U.S. Netanyahu contends only he has the experience and toughness to confront these challenges. Herzog says the prime minister's approach has only made these problems worse and he's also criticized Netanyahu's economic record.

"There is a sense of public fatigue with Netanyahu," said Abraham Diskin, professor emeritus of political science at the Hebrew University of Jerusalem. "However, he still benefits from the ideological loyalty of his nationalist camp and the public uncertainty over Herzog's capabilities."

Weeks of Uncertainty?

It may take weeks before the real winner of the election emerges, as party leaders maneuver to forge alliances. Final results are to be announced late Thursday, and only a week later at the earliest will President Reuven Rivlin assign someone to build the next coalition. Under Israel's electoral system, the task goes to the party deemed best able to form a government and doesn't automatically go to the faction with the largest number of parliamentary seats.

Netanyahu, 65, has served six consecutive years as prime minister by winning two elections, and spent three years as premier from 1996-1999. The 54-year-old Herzog, a Tel Aviv lawyer and son of Israel's sixth president, has held several cabinet posts, including the housing and social affairs ministries.

Today's vote, more than two years ahead of schedule, was precipitated by Netanyahu's firing in December of Finance Minister Yair Lapid and Justice Minister Tzipi Livni over policy disputes. Likud's early lead in the polls narrowed as the campaign progressed, especially after Herzog allied his Labor party with Livni's Hatenuah faction to create Zionist Union.

Likud Slipping

An Israel Radio poll published March 13 showed Zionist Union winning 25 seats, Likud 21, and a united ticket of Arab parties in third place with 13. Tied at 11 seats were Economy Minister Naftali Bennett's Jewish Home, which opposes a Palestinian state, and Lapid's Yesh Atid, which bills itself as the champion of the middle class.

Netanyahu has been hurt in this election by a focus on economic issues, especially the rising costs of housing and basic goods. This vulnerability was aggravated by a government watchdog report last month that criticized spending in the prime minister's households.

Kahlon Benefits

One beneficiary of public dissatisfaction with economic policy has been Moshe Kahlon, who as communications minister under Netanyahu brought down the price of mobile phone services by 90 percent. Riding on that success, his new Kulanu party is expected to win about eight seats, polls project. Netanyahu has said he can't form a government without Kahlon, and offered to appoint him finance minister. Kahlon, who quit Netanyahu's previous government, dismissed the offer and has said he could serve under either Herzog or his former boss.

Two veteran factions may find themselves out of Knesset, and that could affect the balance of support for the camps. Some polls have shown Foreign Minister Avigdor Liberman's Yisrael Beytenu, which distrusts concessions to the Palestinians, and Meretz, a leftist party that advocates Palestinian statehood, grazing the newly raised threshold of votes for entering parliament.

Markets Indifferent

Israel's markets have largely shrugged off the election. The country's stock index rose to an all-time high this month and government bonds have rarely yielded less. Several institutional investors say the vote's outcome is irrelevant to their strategies because they expect no major economic upheavals or policy shifts.

If backed by Kulanu and past allies -- Jewish Home, Yisrael Beytenu, and ultra-Orthodox Jewish lawmakers -- Netanyahu would have enough support to form a narrow, right-wing government, even if Zionist Union emerges as the biggest party, polls suggest. Herzog faces a tougher road in forming a coalition, and would probably need support from Arab parties that have never been a part of any Israeli government.

If today's results mirror the latest polls, Rivlin will recommend to Netanyahu and Herzog they form a unity government, Channel 2 television reported last week. Analysts say Herzog is unlikely to join with Netanyahu unless they take turns rotating in the prime minister's seat, an arrangement that has occurred only once in Israel's history, in 1984.