Israelis cast their votes today in the country's general election, with the rightwing opposition leader, Binyamin Netanyahu, and his rival, Tzipi Livni, the centrist foreign minister, neck and neck, according to analysts.

Up to a fifth of voters were thought to be undecided hours before voting began, an unusually high number that reflected disillusionment with all candidates.

After casting her vote in Tel Aviv, Livni urged people to ignore the bad weather and cast a vote for "hope".

"I have just done what I want every citizen in Israel to do — get out of the house, rain or not, cold or hot, go to the polling station, go into the booth, close your eyes, and vote, not out of fear or despair, and think about hope," she said.

In Jerusalem, Netanyahu predicted "a good victory".

The leader of the Likud party, Netanyahu has led the opinion polls for months and most analysts believe he has the best chance of forming a new coalition government, even though his lead has shrunk in recent days. The bloc of rightwing parties that will support him looks likely to be enough for a majority in the Israeli parliament, the Knesset.

Even if the Kadima party emerges slightly ahead analysts think Livni would struggle to put together a like-minded majority coalition. "Netanyahu has the biggest bloc," said Yossi Verter, a political commentator for the left-leaning Ha'aretz newspaper. "It will be very difficult for Livni to form a government, even if Kadima turns out to be the bigger party, because every government would depend on a rightwing party and the right wing will always quit the coalition whenever there is some progress with the Palestinians or the Syrians."

Verter said it was most likely that Avigdor Lieberman, the populist far-right leader, would join Netanyahu in a new government. Only a few weeks ago, Netanyahu had a solid poll lead, reinforced by Israel's war in Gaza. However, in the final days of the campaign he began to lose support to Lieberman and his popular attacks on Israel's Arab minority. The last polls, released on Friday, gave Likud between 25 and 27 seats in the 120-seat Knesset and Kadima 23 to 25 seats.

"A large part of the Israeli public is indifferent. They don't see much of a difference between Likud and Kadima," said Yaron Ezrahi, a professor of political science at the Hebrew University in Jerusalem.

He said a Netanyahu government would be likely to resist all but the most intense international efforts to forge a peace deal with the Palestinians. "There would be a coalition that tries to be tougher on the negotiations with Obama, with Europe and with moderate Arab countries, and tends to stall any agreement rather than move vigorously [to] a settlement."

Nahum Barnea, a leading columnist, argued in yesterday's Yedioth Ahronoth newspaper that the campaign demonstrated that Israel's political establishment "no longer meets the needs of the country and society". "The larger they are on the billboards, the more they are dwarfed by the country's problems," he wrote.

Pouring rain and strong winds today were expected to keep voter numbers low. Turnout at the last election in 2006 was 63.2%, the lowest in Israel's history.

Lieberman called the rain a "blessing" as he cast his ballot in the settlement of Nokdim. "Our people will come out and vote even if there's a hurricane," he said. His Yisrael Beiteinu party pledges to get tougher with Palestinians, including Israeli Arab citizens, and keep Jewish settlements in the occupied West Bank. In the Arab Israeli town of Umm el-Fahem police were forced to intervene to prevent a clash between a hardline Jewish legislator and Israeli Arabs.

Police spokesman Micky Rosenfeld said officers whisked election observer Arieh Eldad, of the nationalist Ichud Leumi (National Union) party, out of the town after "tensions rose" between him and residents, who hurled stones at police. Five Israeli Arabs were arrested but there were no injuries.

After the results of the election are formally published next week, the president, Shimon Peres, will consult the leaders of all parties and choose one to form a coalition within 42 days. In the past, the president has always turned to the leader of the largest party, although the law allows him to choose a smaller party if it is more likely to form a majority.