Sitting in her office in Parliament on Wednesday afternoon, Idit Silman, a hard-right lawmaker, flicked through hundreds of recent text messages from unknown numbers.
Some were laced with abusive language. Some warned she was going to hell. All of them demanded that her party abandon coalition negotiations with an alliance of centrist, leftist and right-wing lawmakers seeking to replace Prime Minister Benjamin Netanyahu for the first time in 12 years.
“It’s very hard,” Ms. Silman said. “People would rather put pressure on Idit Silman than see Benjamin Netanyahu leave Balfour Street,” she added, in a reference to the location of the prime minister’s official residence.
As opposition negotiators race to meet a midnight deadline to agree on a new government, supporters of Mr. Netanyahu and his Likud party were working overtime to pressure Ms. Silman and other members of the Yamina party, which is one of the few remaining holdouts against an agreement.
Yamina is a pro-settlement party that opposes a Palestinian state and seeks the annexation of much of the occupied West Bank. Many right-wing Israelis therefore see its members as traitors for considering abandoning Mr. Netanyahu, a fellow right-winger, and for negotiating to join a more heterogenous alliance that includes supporters of Palestinian sovereignty and curbs on settlement expansion.
This onslaught has given Ms. Silman and her colleagues pause for thought — and an incentive to be seen as prolonging the negotiations for as long as possible. Even if Yamina does finally join the coalition on Wednesday night, Mr. Netanyahu’s party, Likud, is likely to continue to play on these fears.
On Wednesday, Israeli media reported that pro- and anti-coalition crowds of demonstrators were gathered outside the Jerusalem hotel where negotiations were under way, with police officers keeping them apart.
The vagaries of Israeli legislative protocol mean that Parliament might not hold a vote of confidence in the new government for another 10 days, giving Mr. Netanyahu more time to persuade Yamina lawmakers to reverse course.
His party has already promised to keep goading Ms. Silman and her colleagues.
“Behind the scenes,” said a senior Likud official, speaking on the condition of anonymity, “the Likud party is ramping up the pressure, particularly on the weakest links.”
The pressure has been relentless for days, since the numbers of Ms. Silman and her colleagues, they say, were posted on several WhatsApp and Facebook groups. That has prompted a barrage of messages — and not just from Israelis. Evangelical pastors in the United States have weighed in, and so have Hasidic activists in Britain, among many others.
The Likud party denies accusations that it posted any numbers publicly.
The intimidation has not just come by phone.
When Ms. Silman turned up at her local synagogue last week, she found several slick posters outside, each with her portrait overlaid with the slogan: “Idit Silman stitched together a government with terror supporters.”
For days, protesters have picketed her home, shouted abuse at her children, and trailed her by car in a menacing fashion, she said.
Yamina’s leader, Naftali Bennett, decided to negotiate with the opposition on Sunday night, after months of wavering. His calculus was based on realism, analysts say: Mr. Netanyahu cannot form a coalition, even with Mr. Bennett’s support. So Mr. Bennett can either fall in with the opposition, who have offered him the chance to be prime minister — or force the country to a fifth election in little more than two years.
But the abuse from supporters has prompted the party to delay their final decision until the 11th hour.
“We always ask ourselves this question,” Ms. Silman said on Wednesday afternoon. “Is it right? Can we do something else?”