The extremist Israeli Jewish Power party, headed by National Security Minister Itamar Ben-Gvir, has placed an advertisement criticising Ronen Bar, the head of the country's Shin Bet intelligence agency, in a sign of further divisions within the Israeli government.
The advert, which appeared in Israeli newspapers on Sunday, featured the party's logo and a photo of Bar and warned against a "reckless" deal to end the war on Gaza.
"Ronen Bar failed on October 7 and is leading Israel to another security disaster," it said, the Haaretz newspaper reported.
"Say no to a reckless deal."
Monthslong efforts by mediators to reach a deal that would secure a ceasefire in Gaza and the exchange of Israeli and Palestinian captives have so far been unsuccessful.
Israel's war on Gaza has so far killed at least 40,405 people, according to the coastal enclave's health ministry.
A Hamas-led 7 October attack on southern Israel resulted in the deaths of 1,199 people, according to an AFP tally based on Israeli official figures.
Of 251 captives seized in the attack, 105 remain in Gaza, including 34 the Israeli military says are dead.
Bar, the head of Shin Bet , previously sent a letter to Israeli Prime Minister Benjamin Netanyahu and senior ministers about terrorism by extremist Israeli settlers, with his remarks published on Thursday by Channel 12 News.
"I'm writing you this letter in pain, great fear, as a Jew, as an Israeli, and as a member of a security force about the growing phenomenon of Jewish terrorism from the Hilltop Youth," Bar wrote, referring to one of the most radical factions in the Israeli settler movement.
"The damage to the State of Israel, especially now and to the vast majority of the settlers, is indescribable: global delegitimisation, even among our greatest allies."
Both Bar and Israeli Defence Minister Yoav Gallant have accused Ben-Gvir of endangering the country.
Bar's letter mentioned a storming of the Al-Aqsa Mosque compound in occupied East Jerusalem that Ben-Gvir participated in. The incident saw Jews praying at the site – a breach of the longstanding status-quo agreement in force at the site.
Under the agreement, prayer is reserved for Muslims at Al-Aqsa, which is the third most holy site in the Islamic faith.
Ben-Gvir on Friday hit out at Bar and Gallant after four settlers were arrested on suspicion of engaging in "terrorist acts against Palestinians".
"The captains of the failure, Ronen Bar and [Defence Minister Yoav] Gallant, the father of the [pre-7 October] misconception, continue to harass patriots," he said.
"The head of the Shin Bet, who sent 'an emergency letter' should have received a letter of dismissal by October 8.
"The ongoing failure in his and the defence minister's behaviour should end, the sooner, the better."
Yair Lapid, the leader of the opposition in Israel's parliament, hit out at Ben-Gvir.
"Only an unstable clown like Ben-Gvir is capable in the middle of the war, while residents in the north are in shelters and soldiers are getting killed, of paying for an ad attacking the head of the Shin Bet who is a patriot and a real fighter like Ben-Gvir never was and never will be," he said.
Agencies contributed to this report.