Analysts are predicting a close race between Mr Netanyahu and Ms Livni
Politicians in Israel are making their final appeals to voters before a general election on Tuesday.
The favourite to become prime minister is Binyamin Netanyahu, leader of the right-wing opposition party, Likud.
But his opinion-poll lead has been clawed back in recent weeks by Tzipi Livni, who heads the centrist Kadima, the largest party in the government.
The BBC's Tim Franks, in Jerusalem, says opinion polls suggest the far-right will make the biggest gains.
The final polls on Friday showed the Israel Beiteinu Party led by Avigdor Lieberman eclipsing Labour as third party in the Israeli Knesset.
The party advocates annexing Israel's settlements on the West Bank, and redrawing the borders so that Israel's large Israeli-Arab minority comes under the control of the Palestinian Authority.
But our correspondent says the apparent resurgence of Foreign Minister Ms Livni makes the outcome of the election difficult to predict.
The candidates were due to take part in campaign events around Israel on Monday in a final push for votes.
Front runner Mr Netanyahu visited the Golan Heights on Sunday. He said he would not hand the territory, occupied by Israel in the 1967 Arab-Israeli war, back to Syria, in line with his centre-right platform on security.
In recent days he has been warning right-wing voters that backing Mr Lieberman instead of Likud might hand Ms Livni's Kadima party a narrow victory.
Despite what analysts say is a shift to the right among Israeli voters, centrist Ms Livni on Sunday emphasised her commitment to US-sponsored peace talks.
"I will continue down the path I laid out with my partners on the Palestinian side," Ms Livni told Israel radio.
"I'm not prepared to be a prime minister whose hands are tied in a government without any peace process. That is an intolerable price," she said.
Correspondents say that even if Ms Livni does edge ahead of Mr Netanyahu on polling day, right-wing parties are forecast to dominate the Knesset and she may struggle to form a coalition.
Campaigning has taken place against a backdrop of continuing violence between Israeli forces and Palestinian militants in the Gaza Strip, in the wake of Israel's recent military operation in Gaza.
On Monday, an explosion killed a 22-year-old Palestinian in northern Gaza.
The election is taking place as violence continues despite the Gaza ceasefire
Security officials from the militant group Hamas said the man was killed by an Israeli tank shell fired from across the border, but Israel's military said it was unaware of any such incident.
There were also Israeli air strikes against targets in Beit Lahiya in northern Gaza and in Khan Younis in the south, with no reports of injuries.
On Sunday, Palestinian militants fired a rocket salvo which caused damage but no injuries.
The Israeli government and Palestinian militants have been trying to cement shaky unilateral ceasefires that ended Israel's 22-day offensive in Gaza three weeks ago.
The threat of sporadic rocket fire from the Hamas-controlled Gaza Strip has been one of the top issues in the election.
Current Israeli Prime Minister Ehud Olmert announced several months ago that he was stepping down in the face of numerous investigations into alleged corruption.
An attempt to form a new government without elections failed.
Despite there being vital issues facing Israel - including the fallout from the recent conflict in Gaza - observers say the current campaign has been surprisingly low key.