Israeli parliament paves way for yet another election
A deal to avert a new election must be reached before 11:59pm local time (9:59pm GMT), following a deadlocked vote in September.
But Netanyahu and Gantz, both of whom have repeatedly failed to build a governing majority in the Knesset, or parliament, have spent days trading blame for failing coalition talks.
On Wednesday morning the Knesset passed 50-0 a preliminary reading of a bill immediately dissolving parliament and setting a new election for 2 March.
It must face three more plenary readings and votes during the day before being passed.
New elections would add to the political challenges facing Netanyahu - Israel's longest serving premier, now governing in a caretaker capacity - at a time when, weakened by corruption charges, he must fend off internal challengers in his right-wing Likud party.
Netanyahu and Gantz, a former armed forces chief who heads the Blue and White coalition, had been discussing a potential unity government, but disagreed on who should lead it.
Last month, when Netanyahu was indicted on corruption charges, Gantz called on him to step down.
On Tuesday night Netanyahu called on Gantz to stop "spinning".
"After 80 days, it's time that for one day, for the citizens of Israel, we sit and have a serious discussion about forming a broad unity government. It's not too late," he said on social media.
Gantz said his party was making "efforts to find a way to form a government without us giving up the fundamental principles that brought us into politics".
If the election is confirmed, as is likely, it would be the first time in Israeli history that three elections are held within 12 months.
Lieberman refuses to break deadlock
The parties of Netanyahu and Gantz were nearly deadlocked in September's election, following a similarly inconclusive poll in April.
Israel's proportional system is reliant on coalition building, and both parties fell well short of the 61 seats needed to command a majority in the 120-seat Knesset.
Both were then given 28-day periods to try and forge a workable coalition but failed, forcing President Reuven Rivlin to turn to parliament with his deadline for Wednesday.
New elections are deeply unpopular with the Israeli public, which has expressed mounting anger and frustration with the entire political class.
Both parties had been trying to convince Avigdor Lieberman, a crucial kingmaker, to join their blocs.
But the former nightclub bouncer, whose extreme nationalist Yisrael Beitenu party holds the balance of power, has refused.
Kann Radio reported Tuesday that Netanyahu had abandoned hopes of earning Lieberman's endorsement.
Lieberman pointed out that Likud and Blue and White wouldn't need his support if they could agree to work together.
"If during the next 24 hours a government is not formed it will be solely because the leaders of the two big parties - Likud and Blue and White - were not willing to set aside their egos," he said on Facebook Tuesday.
"All the rest is lies and excuses."
A fourth election?
Netanyahu was indicted last month for bribery, breach of trust and fraud relating to three separate corruption cases.
He denies the allegations and accuses the media, police and prosecution of a witch-hunt.
No date has yet been set for the beginning of the proceedings and, under Israeli law, Netanyahu can remain in office despite an indictment.
He also faces a potential challenge from within his own Likud party.
To boost his support, Netanyahu has pushed his plan to annex the Jordan Valley area of the occupied West Bank, as well as signing a defence treaty with the United States.
He is a close ally of US President Donald Trump, who has taken a number of steps in support of Netanyahu's agenda, such as moving the American embassy to Jerusalem and attempts to legitimise illegal Israeli settlements in the West Bank.
Blue and White, meanwhile, pledged Monday to run with only one leader in the next election - Gantz.
Previously Yair Lapid, second in command in the coalition, was meant to alternate the premiership, but on Monday Lapid said: "We'll all get behind Benny Gantz, our candidate for prime minister."
Despite Netanyahu's indictment, polls suggest that a third round of elections could still be neck and neck - prompting some Israelis to speculate about yet another electoral stalemate.
A commentary writer for the Israel Hayom newspaper suggested that "a fourth election is even now visible on the horizon sometime in early September 2020".