Israeli Prime Minister Benjamin Netanyahu and rival Benny Gantz were wrapping up another bitter election campaign on Saturday, before voters cast their ballots for the third time in 12 months.

Netanyahu, Israel's longest-serving leader, has been charged on several counts of corruption but is battling fiercely to maintain his grip on power.

After inconclusive elections in April and September, latest opinion polls put the two opponents neck and neck in a gruelling political triathlon.

According to the projections, Netanyahu's right-wing Likud and Gantz's centrist Blue and White alliance would each win 33 seats in the 120-member Knesset, Israel's parliament, in Monday's polls.

That result would be almost identical to the previous round, after which each leader tried and failed to form a government.

Neither Netanyahu (R) nor Gantz managed to form a government despite intense coalition negotiations after the last election in September
Neither Netanyahu (R) nor Gantz managed to form a government despite intense coalition negotiations after the last election in September AFP / JACK GUEZ

In previously unannounced television interviews aired separately Saturday evening, Gantz and Netanyahu ripped into each another.

Netanyahu told private Channel 12 that his opponent, a decorated former head of Israel's armed forces, was "not fit to be prime minister" of Israel.

"He is weak, he's not a leader," the incumbent said.

The same interviewer earlier asked Gantz if he would join a coalition under Netanyahu if the third round also failed to produce a clear winner.

"There is no situation in which I will sit under Netanyahu as prime minister when he has three charges against him," Gantz replied.

Netanyahu visits a medical centre during a campaign overshadowed by the COVID-19 virus outbreak
Netanyahu visits a medical centre during a campaign overshadowed by the COVID-19 virus outbreak POOL / Heidi Levine

The opinion polls show that even with their respective allies -- the right and Jewish Orthodox parties for Netanyahu and the centre-left for Gantz -- neither side could gather the 61 seats necessary to form a viable coalition.

Later Saturday, the leaders were to speak at final pre-election rallies, both in the Tel Aviv area.

Judging from a barrage of social media messages, their central goal will be to get their voters out.

With a country largely jaded by three general elections in less than a year along with municipal polls in between, voter turnout is the great unknown.

In Israel's last general election in September, turnout was 1.5 percentage points higher than in April, largely due to an unexpected surge in Arab votes.

Both Gantz and Netanyahu have backed US President Donald Trump's Middle East peace plan
Both Gantz and Netanyahu have backed US President Donald Trump's Middle East peace plan AFP / HAZEM BADER

Israeli Arab parties, united in the Joint List alliance, garnered 13 Knesset seats, making them the third-largest grouping, after Blue and White's 33 and Likud's 32.

This time around they hope to do better still, due to Arab voters' opposition to US President Donald Trump's controversial Middle East peace plan, which is supported by both Netanyahu and Gantz.

"We want the fall of Netanyahu because he is the greatest inciter against Arab citizens and the godfather of the 'Deal of the Century'," Joint List leader Ayman Odeh said, using a common nickname for the Trump plan.

The plan endorses the Jewish state's major priorities at the expense of the Palestinians, who gave no input to the Trump initiative and rejected it immediately.

There is another new element in this third round -- the novel coronavirus.

Over the past 10 days, electioneering has shared media headlines with the global COVID-19 epidemic which has reached Israel with six officially confirmed cases of infection.

Israeli authorities have set up a call centre to screen potential cases and reassure the public, and Israel has entry to foreign travellers from various countries, most recently Italy.

Internal Security Minister Gilad Erdan has warned against potential attempts to spread false rumours about the outbreak in order to diminish voter turnout.

On the boulevards of Jerusalem and Tel Aviv, posters from the Netanyahu camp urge his supporters to come out on polling day to support their leader, whose graft trial opens on March 17 in Jerusalem.

In November, the 70-year-old, who has spent 14 years as prime minister, became the only head of government in the history of Israel to be indicted while in office.

He is charged with corruption, embezzlement and breach of trust.

But if, with his allies, he can win a majority of seats in parliament, Netanyahu will be able to appear before the courts in a position of strength and keep his job as prime minister, at least until justice has run its course with all appeals exhausted.

If he cannot control 61 seats, he will find himself embroiled in frenzied horse-trading to try to stay on at the head of a coalition at the very moment when his trial for corruption begins.