JERUSALEM — Israel is set to swear in a new government on Sunday that will send Prime Minister Benjamin Netanyahu into the opposition after a record 12 years in office and a political crisis that sparked four elections in two years.

Naftali Bennett, the head of a small ultranationalist party, will take over as prime minister. But if he wants to keep the job, he will have to maintain an unwieldy coalition of parties from the political right, left and center.

The eight parties, including a small Arab faction that is making history by sitting in the ruling coalition, are united in their opposition to Netanyahu and new elections but agree on little else. They are likely to pursue a modest agenda that seeks to reduce tensions with the Palestinians and maintain good relations with the U.S. without launching any major initiatives.

Netanyahu, who is on trial for corruption, remains the head of the largest party in parliament and is expected to vigorously oppose the new government. If just one faction bolts, it could lose its majority and would be at risk of collapse, giving him an opening to return to power.

The country’s deep divisions were on vivid display as Bennett addressed parliament ahead of the vote. He was repeatedly interrupted and loudly heckled by supporters of Netanyahu, several of whom were escorted out of the chamber.

Bennett’s speech mostly dwelled on domestic issues, but he expressed opposition to U.S. efforts to revive Iran’s nuclear deal with world powers.

“Israel will not allow Iran to arm itself with nuclear weapons,” Bennett said, vowing to maintain Netanyahu’s confrontational policy. “Israel will not be a party to the agreement and will continue to preserve full freedom of action.”

Bennett nevertheless thanked President Joe Biden and the U.S. for its decades of support for Israel.

Netanyahu, speaking after him, vowed to return to power. He predicted the incoming government would be weak on Iran and give in to U.S. demands to make concessions to the Palestinians.

“If it is destined for us to be in the opposition, we will do it with our backs straight until we topple this dangerous government and return to lead the country in our way,” he said.

Yohanan Plesner, president of the Israel Democracy Institute, a nonpartisan think tank, said the new government will likely be more stable than it appears.

“Even though it has a very narrow majority, it will be very difficult to topple and replace because the opposition is not cohesive,” he said. Each party in the coalition will want to prove that it can deliver, and for that they need “time and achievements.”

Still, Netanyahu “will continue to cast a shadow,” Plesner said. He expects the incoming opposition leader to exploit events and propose legislation that right-wing coalition members would like to support but can’t — all in order to embarrass and undermine them.

The new government is meanwhile promising a return to normalcy after a tumultuous two years that saw four elections, an 11-day Gaza war last month and a coronavirus outbreak that devastated the economy before it was largely brought under control by a successful vaccination campaign.

The driving force behind the coalition is Yair Lapid, a political centrist who will become prime minister in two years, if the government lasts that long.

He called off a planned speech to parliament, instead saying he was ashamed that his 86-year-old mother had to witness the raucous behavior of his opponents. In a brief speech, he asked for “forgiveness from my mother.”

“I wanted her to be proud of the democratic process in Israel. Instead she, along with every citizen of Israel, is ashamed of you and remembers clearly why it’s time to replace you,” he said.

The new government is expected to win a narrow majority in the 120-member assembly, after which it will be sworn in. The government plans to hold its first official meeting later this evening.

It’s unclear if Netanyahu will move out of the official residence. He has lashed out at the new government in apocalyptic terms and accused Bennett of defrauding voters by running as a right-wing stalwart and then partnering with the left.

Netanyahu’s supporters have held angry protests outside the homes of rival lawmakers, who say they have received death threats naming their family members. Israel’s Shin Bet internal security service issued a rare public warning about the incitement earlier this month, saying it could lead to violence.

Netanyahu has condemned the incitement while noting that he has also been a target.

His place in Israeli history is secure, having served as prime minister for a total of 15 years — more than any other, including the country’s founder, David Ben-Gurion.

Netanyahu began his long rule by defying the Obama administration, refusing to freeze settlement construction as it tried unsuccessfully to revive the peace process. Relations with Israel’s closest ally grew even rockier when Netanyahu vigorously campaigned against President Barack Obama’s emerging nuclear deal with Iran, even denouncing it in an address to the U.S. Congress.

But he suffered few if any consequences from those clashes and was richly rewarded by the Trump administration, which recognized contested Jerusalem as Israel’s capital, helped broker normalization agreements with four Arab states and withdrew the U.S. from the Iran deal.

Netanyahu has portrayed himself as a world-class statesman, boasting of his close ties with Trump and Russian President Vladimir Putin. He has also cultivated ties with Arab and African countries that long shunned Israel over its policies toward the Palestinians.

But he has gotten a far chillier reception from the Biden administration and is widely seen as having undermined the long tradition of bipartisan support for Israel in the United States.

His reputation as a political magician has also faded at home, where he has become a deeply polarizing figure. Critics say he has long pursued a divide-and-conquer strategy that aggravated rifts in Israeli society between Jews and Arabs and between his close ultra-Orthodox allies and secular Jews.

In November 2019, he was indicted for fraud, breach of trust and accepting bribes. He refused calls to step down, instead lashing out at the media, judiciary and law enforcement, going so far as to accuse his political opponents of orchestrating an attempted coup. Last year, protesters began holding weekly rallies across the country calling on him to resign.

Netanyahu remains popular among the hard-line nationalists who dominate Israeli politics, but he could soon face a leadership challenge from within his own party. A less polarizing Likud leader would stand a good chance of assembling a coalition that is both farther to the right and more stable than the government that is set to be sworn in.