Acting Prime Minister Ehud Olmert has laid out the choice in stark terms: a vote for his Kadima Party in Tuesday's election is a vote for an Israeli pullback from much of the West Bank.

Barring an unexpected right-wing surge, Israelis will give a green light to that idea in a watershed election that looks set to lead the Jewish state toward separation from most Palestinians after 39 years of occupation.

But the vote is more than a referendum on withdrawal. The makeup of the next Knesset will largely determine the shape of Israel's final borders — and the degree to which they will cut into the territory wanted by Palestinians for a future state.

"This is perhaps the most important election in all of Israel's life," said Mordechai Aviv, 76, who was among about 10 people lined up outside a Jerusalem polling station as voting began.

Even major violence appears unlikely to shake a new Israeli consensus that Israel must quit the main Palestinian population centers if it is to be both Jewish and democratic.

Police were taking no chances Monday, tightening security at West Bank checkpoints and closing off Jerusalem's Al Aqsa Mosque compound to visitors. Officers stood guard on the roofs and balconies of buildings above Jerusalem's Jaffa Road, peering into a crowded market through binoculars.

Olmert voted shortly after polls opened in Jerusalem, accompanied by his wife Aliza. Smiling for the cameras, Olmert slowly slipped the ballot into the box, urging Israelis to follow his example.

"Go and vote ... That's the most important thing. The whole of the Israeli nation. Go and vote," he said.

On the campaign's last day, Labor Party leader Amir Peretz handed out red carnations in Tel Aviv, while Benjamin Netanyahu, head of the rightist Likud Party, said prayers at the Western Wall, Judaism's holiest site. Kadima's No. 2, Foreign Minister Tzipi Livni, chatted with vendors at Jerusalem's main outdoor market, eating a strawberry one of them gave her.

Kadima, the centrist party formed by Prime Minister Ariel Sharon two months before he suffered a massive stroke that left him comatose, is promising divorce — not only from the Palestinians but also from old formulas of "land for peace" and the establishment of a "Greater Israel" incorporating conquered Arab lands.

The lure of divorce has grown stronger in the wake of Hamas militants' rise to power in the Palestinian territories, fueling a go-it-alone approach that is fast becoming the defining characteristic of the Israeli-Palestinian conflict.

Sharon's main legacy has been to plant the idea that Israel need not wait for a formal peace treaty to separate from the Palestinians, and his successor, Olmert, has positioned himself as the man most likely to make that happen.

That helps explain why Olmert, a cigar-smoking former mayor of Jerusalem with a reputation for smugness, is expected to easily become Israel's next prime minister even though he's not particularly liked.

"The reason I believe that Kadima has persisted is because it was never about Sharon but about finally giving expression to the one political camp in this country that until now has been consistently underrepresented, the centrist majority that is hard-line on security but pragmatic on territory," said Yossi Klein Halevi, a senior fellow at the Shalem Center think tank in Jerusalem.

After Sharon's Jan. 4 stroke, poll numbers showed Kadima winning about 40 of the 120 parliament seats up for grabs. That number has dropped to 35 seats or less, according to most polls, with the left-of-center Labor Party coming in second with around 20 seats and Likud a distant third with about a dozen seats — a stunning decline for the party that ruled Israel for most of the past three decades.

With Israel's traditional right-left divide largely replaced by an emerging consensus on the need to "disengage" from the Palestinians — and with Kadima considered a shoo-in for forming the next government — the elections have been described as the dullest in Israeli history.

But many questions remain unanswered:

— Will right-wing parties, aligned with religious forces, be able to pull off a last-minute upset, forming a "blocking majority" of 60 seats instead of the 52 or so predicted by current polls?

— Will left-wing parties win enough seats to force Kadima to take a softer stance toward the Palestinians, perhaps altering plans to incorporate large swaths of West Bank territory in any future pullback?

— Will Kadima need to rely on Arab parties to form a ruling coalition?

— Will Olmert ask Avigdor Lieberman, head of a surging right-wing party that advocates redrawing borders to exclude Arab citizens from Israeli territory, to join a coalition?

Olmert made it clear in pre-election interviews that he planned to withdraw from much of the West Bank and draw Israel's final borders within four years, a surprising deviation from previous candidates who kept post-vote policy plans deliberately vague.

But in the absence of peace talks, few expect Olmert's borders to look anything like the kind of state Palestinians envision for themselves, with expanded Israeli settlement blocs jutting far into the West Bank.

"Kadima is certainly a party of unilateralism and of singlehandedly dictating the borders of both states," said Palestinian lawmaker Hanan Ashrawi. "We don't see that there is any peace movement or camp in Israel that is emerging in order to accept the requirements of a two-state solution and of a negotiated settlement based on international law."