Prime Minister Benjamin Netanyahu of Israel on Sunday fired his defense minister, Yoav Gallant, setting off raucous late-night protests, a day after Mr. Gallant became the first member of his cabinet to call for a halt to the government’s contentious plan to weaken the country’s judiciary.
Announced in a one-line statement by the prime minister’s office, the dismissal intensified an already dramatic domestic crisis — one of the gravest in Israeli history — set off by the government’s proposal to give itself greater control over the selection of Supreme Court justices and to limit the court’s authority over Parliament.
Mr. Gallant’s dismissal set off chaotic and spontaneous late-night demonstrations in and around Tel Aviv, where protesters blocked a major highway and set fires in at least two roads, and in Jerusalem, where crowds broke through police barriers outside Mr. Netanyahu’s private residence.
The crisis has already spurred one of Israel’s biggest-ever waves of protest, tensions with the Biden administration, unrest in the military — and now, after Mr. Gallant’s criticism and subsequent expulsion from government, rifts in the governing coalition.
Mr. Gallant was fired after he urged on Saturday night that the legislation be postponed, warning that it was causing turmoil in the military and was therefore a threat to Israel’s security.
“The rift within our society is widening and penetrating the Israel Defense Forces,” Mr. Gallant said in a televised speech. The schisms, he said, have caused “a clear and immediate and tangible danger to the security of the state — I shall not be a party to this.”
His warning and dismissal followed a surge in military reservists’ refusing to fulfill their volunteer duty in protest of the judicial overhaul. Military leaders had warned that a decline in reservists, who form a key part of the air force pilot corps, might soon affect the military’s operational capacity.
Mr. Netanyahu did not issue a full explanation for his decision to fire Mr. Gallant. But briefing Israeli news reporters, his office said that Mr. Gallant had not done enough to dissuade reservists from refusing to serve, implying that Mr. Gallant had helped stoke the security risks he warned of.
“We must all stand up strongly against refusals,” Mr. Netanyahu said later on social media, without giving further details.
Mr. Netanyahu’s decision appeared an unmistakable signal that the government intends to proceed with a final vote in Parliament early this week on the first part of its proposed overhaul: a law that would give the government greater control over who sits on the Supreme Court.
What to Know About Israel’s Judiciary Overhaul
Mr. Gallant’s dismissal came at a time of rising military threats for Israel and prompted opposition leaders and military experts to question whether Mr. Netanyahu had put politics over security.
Within the Israel Defense Forces, morale was already falling amid disquiet about the move against the court. The political crisis comes against the backdrop of a growing Palestinian insurgency in the occupied West Bank; rising tensions with Hezbollah, the Lebanese militia; and fear of an imminent confrontation with Hamas, the Islamist group that controls the Gaza Strip.
Mr. Gallant’s firing also raises the possibility of more friction between Mr. Netanyahu and the Biden administration, which has become increasingly vocal about its reservations over the judicial plan.
Mr. Gallant, 64, was appointed less than three months ago, fending off competition from a more extreme member of the coalition with far less military experience. His appointment had eased fears in Washington that Mr. Netanyahu might appoint a far-right lawmaker to oversee Israel’s powerful military, which receives considerable U.S. aid and technical assistance.
A former naval commando, Mr. Gallant had faced calls from former military colleagues to speak out against the judicial overhaul. In recent days, fellow former naval commandos held protests outside his home to put pressure on him to break ranks. And reserve pilots sent him text messages every time one decided to suspend service to protest the court plan.
Responding to his dismissal on social media, Mr. Gallant said, “The security of the State of Israel has always been and will always remain the mission of my life.” There was no immediate announcement about his replacement.
His removal prompted consternation among opposition lawmakers and military analysts.
Yossi Yehoshua, a commentator on military affairs for Yediot Ahronot, a major centrist broadsheet, said on social media that Mr. Gallant’s dismissal at a time of such peril for Israel was “a danger to the security of the state that could cost lives.”
“There is no other way to put it,” Mr. Yehoshua said.
Gideon Saar, an opposition lawmaker and former Netanyahu ally, said on social media that the move was “an act of madness.”
“There is no precedent in Israel’s history for a security minister being fired because he warned, as required by his position, of a security danger,” he said. “Netanyahu is determined to drive Israel into the abyss.”
The Israeli consul general in New York, Asaf Zamir, a former opposition lawmaker, resigned in protest of Mr. Gallant’s dismissal.
But in a chaotic Parliament on Sunday, governing lawmakers appeared to have more pressing concerns, racing to finalize the text of the proposed law as government leaders behind the scenes scrambled to ensure they had the votes to pass it.
Two moderate allies of Mr. Netanyahu announced their support on Sunday for the legislation, squashing rumors that they were about to break ranks. But two other coalition members have backed the call by Mr. Gallant to halt the process. If a third follows suit, the government could lose its majority.
If enacted, the law would complete the first step of a plan to limit judicial authority that has provoked broad unease beyond just the military, including among investors, influential American Jews and Israel’s foreign allies.
Military reservists who have spoken out against the overhaul cite a variety of concerns.
Some oppose weakening the judiciary on principle. But reservists say they also fear being given illegal military orders if the Supreme Court lacks the power to scrutinize government activity adequately. And they fear being charged in international courts if the Israeli justice system is perceived as too weak to prosecute soldiers.
Military leaders have privately said they worry that full-time soldiers may also begin to resign. On Sunday, the military chief of staff, Herzi Halevi, ordered all commanders to speak with their subordinates about the need to keep politics out of the military and maintain cohesion, military officials said.
But despite those warnings, coalition lawmakers on the Constitution, Law and Justice Committee, the body in Parliament tasked with preparing the law’s text, used their majority on the committee on Sunday to hurtle through hundreds of objections raised by opposition lawmakers.
Mr. Netanyahu’s government is determined to pass the law this week, before Parliament breaks for a monthlong recess.
That insistence led to pandemonium in the constitution committee on Sunday, with the chairman, Simcha Rothman, often allowing just seconds for the panel’s members to consider each of several hundred opposition objections before voting on them.
Mr. Rothman proceeded so quickly, and the meeting descended so often into uproar, that it was often hard for lawmakers to follow what was being discussed. Most of the opposition lawmakers on the committee were temporarily expelled by Mr. Rothman, accused of disrupting the process.
“Can you behave yourself like a human being for once?” Karine Elharrar, an opposition lawmaker, said to Mr. Rothman during a particularly bitter exchange.
“I can learn from you how to behave like human beings,” Mr. Rothman replied, sarcastically.
Earlier, Ms. Elharrar had told coalition lawmakers on the committee: “You’re just like the Minions,” referring to the mindless cartoon movie characters.
“You don’t even know what you are voting on,” she said.
The government and its supporters say the change is necessary to make the court more representative of the diversity of Israeli society, and to give elected lawmakers primacy over unelected judges.
Critics say the move would give the government too much power over the judiciary, removing one of the few checks on government wrongdoing, and perhaps lead to authoritarian rule.
The overhaul has become a proxy for much deeper social disagreements within Israeli society related to the relationship between religion and state, the future of Israeli settlements in the occupied West Bank, and ethnic tensions among Israeli Jews.
Orthodox Jews and settlers say the court has historically acted against their interests, and has for too long been dominated by secular judges. Jews of Middle Eastern descent also feel underrepresented on the court, which has mostly been staffed by judges from European backgrounds.
Gabby Sobelman, Ronen Bergman and Myra Noveck contributed reporting.