Knesset member Gadi Eisenkot, an observer in the war cabinet, said Netanyahu had failed on security and the economy and called for elections by year's end. 

Speaking at a conference, the former military chief, whose youngest son was killed in combat in the Gaza Strip in December, said Netanyahu was misleading citizens with slogans of "total victory" against Hamas instead of being truthful about the complexity of the Gaza war, now in its eight month.

"Anyone who says that we'll disband a few battalions in Rafah and then return the hostages is sowing a false illusion," he said. "It will take three to five years to stabilize [Gaza] and then many more years to build an alternative to Hamas."

He said Netanyahu had failed to meet his top 2022 campaign promises, including stopping Iran's nuclear program, formalising diplomatic ties with Saudi Arabia and strengthening the economy.

Israel launched an air and ground offensive in Gaza last October vowing to destroy the Palestinian Islamist militant group Hamas. However, experts have doubted whether that is possible.

In a statement on Telegram, the Likud party said Eisenkot and Israeli war cabinet minister Benny Gantz, Netanyahu's main challenger, were looking for excuses to quit the coalition at the height the war. 

"Instead of pursuing victory, they are engaging in petty politics," Likud said.

Wednesday's exchange was the latest spat in the coalition, raising questions about how long Israel's wartime government could survive as Netanyahu straddles conflicting demands from coalition members and faces global scrutiny over Israel's war conduct, including from top ally the United States. 

More than 36,000 Palestinians have been killed in Israel's assault on Gaza, the blockaded enclave's health ministry said, with thousands more trapped under rubble. 

Earlier in May, Gantz threatened to withdraw his center-right party from the conservative prime minister's broadened emergency coalition by June 8 if Netanyahu did not offer clarity on post-war plans for Gaza.

Gantz has helped broaden support for the government in Israel and abroad, but if he quits, the prime minister would still command a majority in parliament with the backing of ultra-nationalist parties, who angered Washington even before the war and have since called Gaza to be annexed and settled.

Most of its 2.3 million population has been displaced and is experiencing a humanitarian catastrophe as aid organizations report of widespread malnutrition and a collapsed health system.

The war began after Hamas-led fighter attacked southern Israeli communities on Oct. 7, calling for an end to Israel's occupation, killing around 1,200 people and seizing more than 250 hostages, according to Israeli tallies. Around 120 hostages remain in Gaza.