Dozens of prominent Israeli artists and intellectuals declared their support for a Palestinian state on the streets of Tel Aviv on Thursday and quickly found themselves confronted by rightist opponents calling them “traitors” and, according to one report, “Jewish Nazis.”

While angry confrontations between protesters on opposite sides of Israel’s gaping ideological divide are not unknown here, this one came at a delicate time, with international pressure growing on Israel to find a way back to peace talks with the Palestinians. It also occurred in a symbolic place, in front of the building where David Ben-Gurion declared Israeli independence in the spring of 1948.

The group of leftist intellectuals and artists signed the declaration endorsing a Palestinian state on the basis of the 1967 borders and asserting that an end to Israel’s occupation “will liberate the two peoples and open the way to a lasting peace.” Among the signers are about 20 winners of the Israel Prize, the country’s most prestigious award.

The last round of Israeli-Palestinian peace negotiations collapsed in September, soon after they started, when a temporary Israeli moratorium on building in West Bank Jewish settlements expired. The Palestinians refuse to return to talks as long as construction continues, and they want clear terms of reference for negotiations. Israel says it is ready to resume talks, but without preconditions.

Palestinian leaders say that in the absence of a negotiated agreement with Israel they will seek international recognition of a Palestinian state by September at the United Nations.

The signers of the Israeli declaration of support were joined in Tel Aviv by hundreds of leftist sympathizers.

About 30 rightist opponents gathered nearby and began verbally abusing those attending the ceremony. Television images showed rightists holding a sign calling the leftists “traitors” and hurling insults like “criminals.” According to some local news media reports, counterprotesters also called the leftists “Jewish Nazis.”

Afterward, Defense Minister Ehud Barak called on Israelis to “show responsibility” and to drop the word “treason” from public discourse. “The country is facing fateful decisions,” he said, according to a statement from his office. “We all want an Israel that is secure and strong.”

In a television debate, Yariv Ben-Eliezer, grandson of Mr. Ben-Gurion, Israel’s first prime minister, and an academic specializing in communications, accused the signers of the declaration in Tel Aviv of staging a “media gimmick” and of cheapening Israel’s own Declaration of Independence.

Zeev Sternhell, professor emeritus at Hebrew University, an impassioned leftist and an Israel Prize winner for his work in the field of political science, replied that on the contrary, the signers meant to elevate the Israeli Declaration of Independence and ensure Israel’s future with the new avowal of two states for two peoples.

In 2008, Professor Sternhell was wounded when a pipe bomb exploded outside the door of his Jerusalem home. In 2009, the Israeli police charged an American immigrant who lived in a West Bank settlement with the bombing outside the professor’s home and in a string of other attacks.