The key election is being seen as a referendum on Mr Olmert’s bold vision to finalise the final borders of Israel and unilaterally separate from the Palestinians.
Pre-election polling put Mr Olmert, who was catapulted to power when Prime Minister Ariel Sharon suffered a massive stroke 12 weeks ago, in front, despite leading a centrist party that was only formed late last year.
However it is expected to need support from other parties to ensure parliamentary approval to implement the pullout plan.
“We are not going to be able to fulfil all our dreams,” Mr Olmert wrote in an opinion piece for the top-selling Yediot Aharonot newspaper.
“We must preserve the main settlement blocs in Judea and Samaria (the West Bank) and we will fix the route of the security barrier beyond which we will no longer remain.”
The barrier being erected across the occupied West Bank fences off the majority of the quarter of a million Jewish settlers from the 2.5 million-strong Palestinian population.
Casting his ballot, Mr Olmert urged others to do the same, amid fears that voter turnout could be low.
“Go and vote and may this be a beautiful day for the people of Israel,” he said.
About 22,000 police are being stationed outside the 8,000-plus polling stations, and troop reinforcements have been deployed across the country to try to prevent militant attacks.
Police restricted access to the flashpoint Al-Aqsa Mosque/Temple Mount compound, holy to both Jews and Muslims.
According to final pre-ballot opinion polls, Kadima will win 34 seats in the 120-member parliament despite fears of voter apathy which may favour right-wing or religious parties.
The Yediot Aharonot newspaper forecast 21 seats for the centre-left Labor and 13 for the right-wing Likud while a rival poll in the Maariv gave Labour 17, Likud 14 and the extreme right-wing Yisrael Beitenu 12.
Polls predicted that the Labour party, led by Amir Peretz, would emerge the second force in parliament.
But many Israeli voters showed little interest during election campaigning.
<!–"I won't vote. There is no point any more," said shopper Ofer Levy. "No party has the interests of the people at heart anymore."
Political analysts put apathy down partly to the fact that many see a victory for Mr Olmert as a foregone conclusion.–>
Kadima’s proposal to give up some West Bank settlements and strengthen others to impose a border with the Palestinians is popular among Israelis tired of conflict.
Some analysts also saw the victory of Hamas in Palestinian elections earlier this year as a factor, noting that even more dovish parties were not talking of peace with a group that is formally committed to destroying Israel.
<!–Hamas suggests dialogue
Meanwhile, incoming Palestinian premier Ismail Haniya laid out the platform of his Hamas government in a keynote address to politicians.
Mr Haniya said his Hamas government was ready to talk to the international community to end the Middle East conflict but would not change its hardline stance on Israel.
“Our government will spare no effort to reach a just peace in the region, putting an end to the occupation and restoring out rights,” he told MPs.
“We have never been supporters of war, terrorism or bloodletting. Instead it is the Israeli occupation that waged all forms of terrorism against our people in chasing them out of their homeland, besieging it and starving it.”
His rejection of international demands for respect of past peace agreements drew a swift warning from Israel’s outgoing government that the policy would leave Israel no choice but to fix its borders unilaterally.
Mr Haniya, whose Islamist group has been behind dozens of suicide attacks, said Palestinians had the right to continue the independence “struggle”.
He also urged the United States, which considers Hamas a terrorist organisation, to alter its stance towards the Palestinians, and rejected threats from the West to slash funding unless his administration radically alters its hardline platform.
But his offer of dialogue was swiftly rejected by Washington, which insisted Hamas could not bypass demands for it to renounce violence.
A senior Israeli official dismissed the speech and insisted that if Hamas continued in the same vein Israel would have no option but act unilaterally.
“If we see that the Hamas program is the government’s long-term policy, we will take our destiny into our hands,” spokesman Ranaan Gissin told news agency AFP.
Israel has refused to have any dealings with a Hamas-led government and has imposed sanctions including travel restrictions which forced Mr Haniya to deliver his speech to the Ramallah-based parliament via video-link from Gaza City.
The Hamas-dominated administration is expected to take office on Wednesday.–>