Acting Israeli Prime Minister Ehud Olmert said Sunday he planned to get U.S. backing before pushing forward with his plan to withdraw from much of the West Bank, maintain control of major settlement blocs and draw Israel's final borders by 2010.

Meanwhile, candidates made a last-ditch effort to win over voters amid fears of an unprecedented low turnout in Tuesday's election. The three top candidates gave interviews to Israel Radio, trying to clarify their differences and launching final, fierce attacks on their rivals.

Fearing that Palestinian militants could launch a terror attack in the tense days before the vote, Israel's security forces declared a high state of alert beginning Sunday, putting extra forces on the streets and keeping a tight closure on the West Bank.

Meanwhile, soldiers scheduled for duty on Tuesday began voting Sunday.

Following a lackluster campaign that aroused little emotion, pollsters are predicting a voter turnout of around 60 percent, the lowest in Israel's history. In a sign of voter apathy, the blocs of campaign ads broadcast on television over the past three weeks were watched by an average of 14.4 percent of Israelis, their lowest ratings ever, Israel Radio reported.

A low turnout could cause the most damage to Olmert's centrist Kadima Party, which is the clear front-runner, analysts said. Speaking before the weekly Cabinet meeting Sunday, Olmert called on Israelis to go to the polls.

"There is no greater or more significant way to exercise your right as a citizen then that which allows you to decide through a vote the fate of the country and the character of the state's government," Olmert said. "Therefore I tell all the citizens of the state of Israel: Go vote."

A dovish institute took out a full-page ad in the Israeli daily Haaretz on Sunday, warning that low turnout could bring the hawkish Likud leader, former Prime Minister Benjamin Netanyahu, to power.

Amnon Dankner, editor of the Israeli daily Maariv, wrote a lengthy appeal to Israelis: "Get out and vote and ... you will know that you took part in determining your fate with serious and mature deliberation, and did not enshroud yourself with shame and catastrophe because you were spoiled and foolish."

Sunday was the last full day of campaigning before the vote. Political parties are barred from campaigning 24 hours before the election.

In his interview with Israel Radio, Olmert expanded on his plan to determine Israel's final borders, if necessary through unilateral West Bank pullouts.

"I spoke about negotiations with the United States and the international community and I spoke about final borders that the entire international community will support, including the United States," he said. "I have a basis to believe that there is great openness in the United States, and in other places, to listen to these arguments and also to seriously discuss them."

The Palestinians oppose Olmert's plan, saying Israel has no right to retain any settlements and final borders can only be decided through negotiations.

Amir Peretz, head of the dovish Labor Party, which is expected to finish a distant second in the polls, used his last day of campaigning to attack Nobel Peace laureate Shimon Peres, the longtime Labor leader who defected to Kadima after losing a party primary to Peretz.

Pollsters predict that Netanyahu will come in third, a serious blow to the Likud Party that has dominated Israeli politics for most of the past three decades. Netanyahu attacked Olmert and Peretz, but also defended the economic moves he is being lambasted for taking when he served as finance minister under Sharon.

Assuming that Olmert — who replaced Ariel Sharon after the prime minister suffered a massive stroke Jan. 4 — will be the next prime minister, Israel Radio commentators pushed him to talk about the makeup of his government and how he would divvy up Cabinet positions.

Olmert refused to comment on positions, but said only parties that accept his plan to pullout of isolated West Bank settlements could join his government.