Israel 's Shin Bet security service has tightened protection of the prime minister, MPs and parliament ahead of next week's crucial vote on a partial Gaza withdrawal.
In the countdown to the decision, Israel 's political climate has become increasingly explosive.
Some withdrawal opponents have harshly attacked Prime Minister Ariel Sharon, denouncing him as a dictator who is endangering Israel and an opposition leader has said he fears the premier may be a target for Jewish assassins.
Security officials said the Shin Bet is on high alert regarding possible attacks on Sharon, and he was ringed by an unprecedented number of bodyguards this week.
Jewish settler leaders said they would stage a mass rally outside parliament during the vote, which is set for next Tuesday.
Sharon is expected to win a majority, with the help of the moderate opposition Labour Party. Settlers have been pushing for a national referendum, but Sharon has rejected the idea as a stalling tactic.
Israel 's military is increasingly concerned about calls by prominent rabbis to mutiny. Rabbis have asked religious soldiers to refuse orders to participate in the dismantling of settlements in the withdrawal, nearly 9,000 settlers would be removed from their homes.
Defence Minister Shaul Mofaz and his army chief, Lieutenant General Moshe Yaalon, called on rabbis to withdraw their ruling.
"The Israeli Defence Forces is what unites the different parts of this nation," Mofaz said. "Refusal will lead to disintegration. I urge the rabbis who called for refusal - take it back, don't tear us apart."
Some of the army's key officers identify with the Jewish settlement movement. Military analysts said if a significant number of religious soldiers refuse to observe orders, the army could become paralysed.
Labour MP Yitzhak Herzog said another political assassination could occur in Israel . "There are few democracies in the world today who face such a major challenge as Israel will face next week," he said.