"The war cabinet must formulate and approve by June 8 an action plan that will lead to the realization of six strategic goals of national importance.. (or) we will be forced to resign from the government," Gantz said, referring to his party, in a televised address directed at Netanyahu.
Gantz said the six goals included toppling Hamas, ensuring Israeli security control over the Palestinian territory and returning Israeli hostages.
"Along with maintaining Israeli security control, establish an American, European, Arab and Palestinian administration that will manage civilian affairs in the Gaza Strip and lay the foundation for a future alternative that is not Hamas or (Mahmud) Abbas," he said, referring to the president of the Palestinian Authority.
He also urged the normalization of ties with Saudi Arabia "as part of an overall move that will create an alliance with the free world and the Arab world against Iran and its affiliates."
Netanyahu responded to Gantz's threat on Saturday by slamming the minister's demands as "washed-up words whose meaning is clear: the end of the war and a defeat for Israel, the abandoning of most of the hostages, leaving Hamas intact and the establishment of a Palestinian state."
The Israeli army has been battling Hamas militants across the Gaza Strip for more than seven months.
But broad splits have emerged in the Israeli war cabinet in recent days after Hamas fighters regrouped in northern Gaza, an area where Israel previously said the group had been neutralized.
Netanyahu came under personal attack from Defence Minister Yoav Gallant on Wednesday for failing to rule out an Israeli government in Gaza after the war.
The Gaza war broke out after Hamas's attack on October 7 on southern Israel which resulted in the deaths of more than 1,170 people, mostly civilians, according to an AFP tally of Israeli official figures.
The militants also seized about 250 hostages, 124 of whom Israel estimates remain in Gaza, including 37 the military says are dead.
Israel's military retaliation against Hamas has killed at least 35,386 people, mostly civilians, according to the Hamas-run Gaza's health ministry, and an Israeli siege has brought dire food shortages and the threat of famine.