Netanyahu's security cabinet, of which the minister, Bezalel Smotrich, is a member, approved the plan by majority on Friday to expand military operations in the shattered Palestinian enclave to try to defeat militant group Hamas.
The move drew a chorus of condemnation within Israel, where thousands of people protested in Tel Aviv - and abroad - on Saturday calling for an immediate ceasefire and release of hostages held by militant group Hamas.
The United Nations Security Council was expected to meet later on Sunday to discuss the plan, with many countries expressing concern it could worsen already acute hunger among Palestinians.
Netanyahu was expected to give a news conference for international media in Israel and make a televised announcement later in the day. It was not clear what he would say.
Smotrich said he has lost faith in Netanyahu's ability and desire to lead to a victory over Hamas. The new plan, he said in a video on X late on Saturday, was intended to get Hamas back to ceasefire negotiations.
The prime minister and the cabinet have decided to do "more of the same" he said, referring to the fact that Israeli troops have entered the city before and failed to defeat Hamas.
He and other far-right members of Netanyahu's coalition argue the plan does not go far enough but Smotrich stopped short of delivering a clear ultimatum to Netanyahu.
Other far-right coalition allies of Netanyahu have also pushed for total military occupation of Gaza, the annexation of large swaths of the territory and the removal of much of its Palestinian population.
The Israeli military has warned expanding the offensive could endanger the lives of hostages Hamas is still holding in Gaza, believed to number about 20, and draw its troops into protracted and deadly guerrilla warfare.
Italy said Israel should heed its army's warnings.
"The invasion of Gaza risks turning into a Vietnam for Israeli soldiers," Foreign Minister Antonio Tajani told daily Il Messaggero.
He reiterated calls for a UN mission led by Arab countries to "reunify the Palestinian state" and said Italy was ready to participate.
The Security Council is likely to discuss the humanitarian crisis in Gaza and the prospect of its worsening if the Israeli plan goes ahead but there has been little appetite among Arab states to send in troops.
Israel has come under mounting pressure over widespread hunger and thirst in the enclave, prompting it to announce a series of new measures to ease aid distribution.
The Israeli military said on Sunday the contents of almost 1900 aid trucks were distributed last week from the Gaza sides of the Kerem Shalom and Zikim border crossings.
The United Nations has said Gaza needs far more aid.
Medics said a 14-year-old boy was killed on Saturday when an aid airdrop fell on a tent encampment in central Gaza.
The Hamas-run Gaza government media office said his death raised the number of people killed during the airdrops to 23 since the war began.
"We have repeatedly warned of the dangers of these inhumane methods and have consistently called for the safe and sufficient delivery of aid through land crossings, especially food, infant formula, medicines, and medical supplies," it said.
Five more people, including two children, died of malnutrition and starvation in Gaza in the past 24 hours, the health ministry said, taking the number of deaths from such causes to 217, including 100 children.
The war began on October 7, 2023, when Hamas-led militants stormed southern Israel and killed 1200 people, and took 251 hostages. Israeli authorities say 20 of the remaining 50 hostages in Gaza are alive.
Israel's offensive in Gaza has since killed more than 61,000 Palestinians, according to health officials, and left much of the territory in ruins.
