Defiantly railing against attempts to “overthrow” him before donning a face mask to enter court, Benjamin Netanyahu sat for the first day of his high-profile corruption trial, which threatens to put Israel’s longest-serving leader behind bars and open deep divisions within the country. Speaking in the corridors of the courthouse ahead of the hearing, Netanyahu decried police and prosecutors he accused of attempting to topple him. “When there is a strong rightwing leader like me, everything is permitted to bring him down,” he said, flanked by loyal ministers. “This is an attempt to overthrow us.” At the start of the hour-long proceedings, one of the judges – also in face masks and behind clear plastic screens – asked Netanyahu if he had read and understood the charges of bribery, fraud and breach of trust. He responded: “Yes, your Honour.” His lawyer argued for the court to grant a three-month delay to deal with the huge caseload of evidence. The case, with hundreds of witnesses, could last months if not years. Public interest in the trial is so intense that police closed off streets around the court in Jerusalem to prevent crowds from gathering too close. Netanyahu chaired the first official cabinet meeting of his new unity government, sworn in a week ago on Sunday morning. By the afternoon, he had become the first sitting Israeli prime minister to fight criminal charges in court. A poster has been hung above the main highway in Tel Aviv with a photo of the prime minister. “Israel is ashamed,” it said. Netanyahu, 70, has forcefully denied the allegations, calling them a politically motivated witch-hunt. Perhaps fearing negative visuals from courtroom, his lawyers tried and failed to have him exempted from appearing. Ahead of the trial, he battled the allegations outside court, smearing the domestic media and judiciary as conspirators against him, often to the point that he has been accused of stirring up public hatred. Within earshot of the court, supporters of Netanyahu – who has been in power for more than a decade – shouted out his nickname: “Bibi! Bibi! Bibi!” “Wake up the people of Israel,” shouted one protester, Sarit Ayalon, 58, an academic. “The media became a voice for one side,” she said, holding an Israeli flag. Israel’s attorney general, Avichai Mandelblit, who indicted Netanyahu, filed police complaints this month over what he said were coordinated death threats. At the pro-Netanyahu protest, a sign had been erected on which the attorney general’s face had been cut and pasted on to the image of a man in jail. Nahum Barnea, a columnist for the Yedioth Ahronoth newspaper, compared the vitriol against the judiciary to rightwing politicians’ goading of Yitzhak Rabin in the 1990s. After months of incitement for his efforts to reach a peace deal with the Palestinians, the former prime minister was murdered by an ultranationalist extremist. “The campaign that has been mounted against the justice system … is reckless and dangerous,” Barnea wrote. “Netanyahu and his associates … are shutting their eyes as to what this campaign is liable to lead to. They are playing with fire.” Indicted last year in three separate cases, Netanyahu faces more than a decade in prison if convicted. He is accused of accepting expensive gifts including champagne, jewellery and cigars, and colluding with Israeli media magnates to publish favourable stories about him while smearing his political opponents. Unlike one of his predecessors, Ehud Olmert, who stepped down after it appeared he would be indicted, Netanyahu has refused to leave power, and his role as head of the new unity government has bolstered his position. Crucially, the coalition deal he signed affords him extra protection, exempting him from a rule that obliges ministers to resign if charged with a crime. Yuval Shany, vice president of research at the Israel Democracy Institute, warned of a vast conflict of interests in having a prime minister up in court while still in office. “If, God forbid, we have a war, is it because there is a security threat or this is a wag the dog type of moment when you want to distract public attention?” he said. “This is in itself a very unhealthy situation.”