Israeli President Isaac Herzog on Monday said a compromise in the government's judicial overhaul plan could be imminent even as protests against the reform continued to spread. Local media circulated a letter by 10 former air force chiefs to Prime Minister Benjamin Netanyahu warning of the "grave and tangible" threat posed by the judicial overhaul plan, a day after reservists said they would not turn up for training in protest. In a statement late on Monday, Netanyahu criticized the threats to refuse military service, which he said endangered Israel's existence. On the battlefield, soldiers have stood united "throughout all of Israel's wars, regardless of the struggles and disagreements among us," he said, speaking from a Border Police base in the occupied West Bank settlement of Beit Horon. "There is room for protest, there is room for disagreements, for expressing opinions, but there is no room for refusal." Although the presidency is a ceremonial post, Herzog convened 100 heads of authorities for an emergency meeting designed to come up with a solution to proposals that have split the country and led to mass nationwide protests. "We are closer than ever to the possibility of an agreed outline. There are agreements behind the scenes on most things," Herzog said in a statement, without giving details. Herzog's comments sent financial markets sharply higher even though there was no immediate sign of a deal between the government and opposition. He said it would now depend on leaders of the ruling coalition and opposition to "put the country and the citizens above everything else" and implement it, adding that his plan works to placate both sides. Heads of the opposition Yair Lapid and Benny Gantz issued a joint statement in response, commending the president's efforts to reach a compromise but demanding that Netanyahu halt the legislation process to allow for "honest and effective dialogue". "Israel is on the brink of a national emergency - and Netanyahu refuses to stop," they wrote on Twitter. Netanyahu did not immediately respond to Herzog's efforts. Herzog last month floated a compromise plan to spare the country what he described as a "constitutional collapse". The judicial overhaul plan, which has already received initial parliamentary approval, would give the government greater sway on selecting judges and limit the power of the Supreme Court to strike down legislation. Critics of the planned law changes say Netanyahu - on trial on graft charges that he denies - is pursuing steps that will hurt Israel's democratic checks and balances, enable corruption and bring diplomatic isolation. Proponents say the changes are needed to curb what they deem an activist judiciary that interferes in politics. Lapid has called for compromise talks and a freeze of the legislation for 60 days but Netanyahu said he would only agree to negotiations without preconditions. Meanwhile, National Security Minister Itamar Ben-Gvir claimed that some protest leaders were plotting to assassinate both himself and Netanyahu. In an interview on Monday, Ben-Gvir noted that he doesn’t want to generalize and that “most of (the protesters) are good and decent people, but there are those among them who say that Ben-Gvir and Netanyahu should be murdered.” “There are leftist anarchists who some time ago crossed the red line and are planning to kill me and the prime minister,” he alleged. Senior police and intelligence officials denied that such a plot exists. An unnamed senior police official told Kan 11 website that he was unaware of the intelligence cited by Ben-Gvir that protesters were planning a political murder. “We have no intelligence information about the demonstrators threatening to kill the prime minister or the minister of national security. We also checked what other intelligence agencies (the Shin Bet) have, there is no such threat,” the official said. Responding to the claims, Lapid called Ben-Gvir a liar and a “clown.” In a series of tweets, he accused him of “inventing ‘intelligence materials’ that do not exist. This is not only ridiculous, but it is also dangerous.” National Unity party leader Benny Gantz called on Netanyahu to fire Ben-Gvir “before it is too late”. “A person [Ben Gvir] who was involved in [Jewish] terror instead of being drafted into the army is delegitimizing patriotic protesters,” Gantz said in a tweet. Protest leaders were quick to reject Ben-Gvir's claims, urging Netanyahu to sack him.