JERUSALEM - Millions of Israelis voted on Tuesday in a tightly fought election, with Prime Minister Benjamin Netanyahu facing an uphill battle to defeat a strong campaign by the centre-left opposition to deny him a fourth term in office.
In many respects the vote has turned into a referendum on "Bibi" Netanyahu, in power for a total of nine years spread over three terms. If he wins again he would be on track to become Israel's longest-serving prime minister.
Netanyahu's campaign has focused on the threat from Iran's nuclear programme and the spread of militant Islam. But it's a message many Israelis say they are fed up with and as a result the centre-left's campaign on socio-economic issues, especially the high cost of living in Israel, appears to have won more traction with voters.
When the last opinion polls were published on March 13, the centre-left, known as the Zionist Union and led by Isaac Herzog, held a four-seat advantage over Netanyahu's right-wing Likud, a margin that had it set for a surprise victory.
But in the last three days of campaigning, Netanyahu went on a blitz to try to shore up his Likud base and attract votes from other right-wing, nationalist parties, promising more building of Jewish settlements and that the Palestinians would not get their own state if he were re-elected.
Those bold pledges, if carried out, would further isolate Israel from the United States and the European Union. But they may go some way towards convincing voters to plumb for what they know rather than others on the right.
Surveys show around 15 per cent of voters are undecided, meaning the ballot could sway widely - opinion polls have rarely been a precise predictor of Israeli elections in the past.
Voting ends at 2200 local (2000 GMT) on Tuesday, with the first exit polls published immediately afterwards.
If Netanyahu can draw votes from other right-wing parties, he may be able to close the gap with the centre-left and be in a position to be asked first by Israel's president to try to form a governing coalition.
No party has ever won an outright majority in Israel's 67-year history, making coalition-building the norm. It is also an opaque and highly unpredictable game, with any number of allegiances possible among the 10 or 11 parties expected to win a place in the 120-seat parliament, the Knesset.
Since there are more parties on the right and far-right of the spectrum, Netanyahu is probably better placed to cobble together a coalition, even if he narrowly loses the election. But if the centre-left does win by four or more seats, it should get the nod first to try to form a coalition.
Under sunny skies, Netanyahu went to vote early, going with his wife and one of his sons to a ballot box in a school near their family home in Jerusalem. He acknowledged that it was a tight race and urged voters to back the right.
"To prevent the rise to power of a left-wing party, there is only one thing to do - close the gap," he said.
Herzog, who has overcome criticism of his slight stature and reedy voice to lead a resilient campaign, voted in Tel Aviv, where he emphasised that the vote was about a new direction.
"Whoever wants to continue the way of Bibi - despair and disappointment - can vote for him," he said. "But whoever wants change, hope, and really a better future for Israel, vote for the Zionist Union under my leadership."
The son of a former president and the grandson of one of Israel's foremost rabbis, Herzog, 54, is as close as it gets to having a Kennedy-style heritage. While his leadership has been critiqued in the past, he has shown wit and intellect on the campaign trail, bolstering his image among voters.
"For the first time in my life, I'm going to be voting for Labour, that is the Zionist Union," said Dedi Cohen, 39, a lawyer in Tel Aviv. "The risk of Netanyahu building the next government is too big. How long has he been in power? Nine years? It's too much. Enough."
Whatever happens in Tuesday's vote, the key will be in coalition building, with three or four parties critical to how the balance of power ends up tipping.
Moshe Kahlon, the leader of Kulanu, a centrist party that broke away from Likud, is seen as perhaps the most important "kingmaker". A former communications minister credited with bringing down mobile phone prices, Kahlon could ally with either Netanyahu or Herzog, bringing up to 10 seats with him.
Yair Lapid, the leader of the centrist Yesh Atid party, is another power-centre. He also could ally with either the right or the centre-left, bringing somewhere between 12-14 seats with him. But he does not sit comfortably with religious parties, making him less flexible in coalition negotiations.
If the centre-left is to put together a coalition, it needs at least 61 seats, meaning as well as Kahlon or Lapid and the far-left Meretz party, it would need the support of the ultra-Orthodox parties, which are expected to win around 13 seats.
Another factor is the Arab parties, which for the first time have united under one list. That has strengthened their standing with voters and they are expected to win around 13 seats as well. While they are unlikely to join a centre-left coalition, they could give it tacit support in parliament, which could give the centre-left leverage over Netanyahu.