JERUSALEM — As Israel prepared to release another group of 26 long-serving Palestinian prisoners overnight Monday, and was expected to follow quickly with another announcement of new construction in West Bank settlements, Prime Minister Benjamin Netanyahu faced withering criticism from all corners, including conservative members of his own coalition.

Palestinian leaders threatened that any new settlement activity could lead them to seek membership and sue Israel in the International Criminal Court, a move they had promised not to take during peace talks that started this summer. European diplomats warned the Israelis in a series of high-level meetings over the past week against pairing the prisoner release with a construction announcement, as was done twice before. Even the Israeli right-wing forces that Mr. Netanyahu aimed to appease with the settlement initiative distanced themselves from the plan, denouncing any linkage between prisoners and construction as unfortunate or even immoral.

"He is wrong because he tries to please all sides. The result is nobody is happy with his steps," said Eitan Haber, a veteran Israeli commentator, invoking a Hebrew idiom about how a bridegroom cannot dance at two weddings. Mr. Haber, who was a close adviser to former Prime Minister Yitzhak Rabin, added, "If you are a true leader, a real leader, you must choose your way, and go and try to implement your ideas."

Israeli news media reported that plans for 1,400 new housing units, including 600 in East Jerusalem, would be unveiled this week, as Secretary of State John Kerry is scheduled to make his 10th visit to the region to push for a peace agreement. Mr. Netanyahu, who agreed to release a total of 104 Palestinian prisoners over nine months of negotiations rather than freeze settlement construction, said Monday that "the protection of settlement in the land of Israel" is one of the nation's "vital interests."

"Leadership is judged by its ability to take hard decisions," the prime minister told lawmakers with his Likud faction. "The state of Israel, I believe, has a strategic interest in the existence of diplomatic negotiations whose goal is to achieve an agreement that will end the conflict."

The prisoners scheduled for release have served 19 to 28 years, most for involvement in the murder of Israelis. They included Kamil Awad Ali Ahmad, who was convicted in the killing of an Israeli soldier as well as 15 Arabs suspected of collaborating with Israel, and Adnan Afandi, who was 21 when he stabbed and wounded two Israeli teenagers at a Jerusalem market in 1992.

Bella Freund, an Israeli mother of eight, recalled in an interview on Monday that she had used her body to protect Mr. Afandi from a furious mob for 27 minutes until the police arrived that day, and now felt betrayed. "I delivered the terrorist alive to justice, and justice gave me a slap in the face," she said.

The prisoner group also included, for the first time, at least five residents of East Jerusalem, which provoked particular outrage among Israelis. "These people will be neighbors of the families of the victims they murdered," Ortal Tammam, whose uncle Moshe was killed at age 19 by Israeli Arabs in 1984, said in the Israeli daily Maariv. "They'll be able to go to the same places of recreation, ride the same buses," she said, "so the blow is even greater."

Israelis opposed to the prisoner release have spent the last several days camped outside the prime minister's office in a tent adorned with portraits of people killed in recent attacks alongside victims of decades ago. "Ministers of the government of Israel, you should be ashamed!" read one poster. Another, with an image of Mr. Netanyahu, said, "Not a leader, a liar."

Lizi Hameiri, 32, a volunteer for the Israeli victims group that has led protests against the releases, said Mr. Netanyahu's repeated announcements of new settlement construction only "adds insult to injury."

"Can a house compensate for the loss of a human life?" Ms. Hameiri asked. "It's insane, infuriating, and immoral."