For many Israelis, the size of Saturday night’s protests against the high cost of living and for social justice will serve as a barometer of whether the popular movement that began in this Mediterranean city and swept the country this summer is thriving or fading.

After six weeks of tent encampments and rallies featuring popular singers that drew as many as 300,000 people into the streets on the first Saturday in August, the Sept. 3 rally has been described by its promoters as a million-person march.

But for now the movement is in a kind of hiatus, with nagging questions about where it will go. The mid-August attack by Palestinian militants that killed eight Israelis near the southern city of Eilat, close to the Egyptian border, followed by Israeli airstrikes on Gaza and Palestinian rocket attacks from Gaza, proved to be a major interruption, abruptly changing the public discourse back to the more familiar mode of Israeli security in hostile surroundings.

In addition, disagreements have emerged among the groups that make up the leadership of the protest movement, along with increasing grumbling about some of the higher-profile leaders themselves. The giddy festival atmosphere that first enveloped the social protest has dissipated. The rows of tents at the flagship encampment lining Rothschild Boulevard in Tel Aviv are gradually emptying.

After Saturday’s rally, some or most of the tent encampments around the country may decide to fold. But the activists who are most dedicated to the movement are playing down the divisions, determined to carry on.

“Sitting in tents is a means, not a goal,” said Yoav Fekete, 27, a newly elected representative of the Rothschild encampment. “People have to get back to work and school.”

The members of a committed group of about 100 people are “not going anywhere,” he said, and there are plans to form “communities” around the country where people will hold popular meetings and “take responsibility for the space they live in.”

Ella Doron, 29, a singer, established a compound in the Rothschild encampment called Villa Favela — a cluster of temporary shelters that included carpeted private quarters with a double bed. “Of course people have left,” she said. “You cannot be on full power for a month and a half. The tents are a symbol, a form of protest right now.”

The test facing the social protest movement goes to the core of an Israeli problem: whether the national agenda can ever be shaped by issues other than the country’s security threats and related dictates of the Israeli-Arab conflict.

In the headier days before the attack near Eilat, the wave of protest, which began over the lack of affordable housing, grew to encompass every aspect of an Israeli society battered by rising costs, with a struggling middle class and a growing gap between the rich and the poor. The protest managed to unite a normally fractious public, momentarily creating common cause among the left and the right, religious and secular Israelis, Ashkenazim of European origin and Sephardic Jews from Middle Eastern backgrounds, and the country’s Arabs and Jews.

The debate had turned to the need to reduce the country’s formidable defense budget, with economists and security experts explaining how it could be done.

“At last,” Stav Shaffir, one of the protest leaders, said in an interview shortly before the attack. Israelis had been made to feel that they should not complain about material things, she said, because “the perception is always that something can happen tomorrow and we will all be dead.”

Since then the social justice movement has been bumped off the front pages of the Israeli newspapers. Rockets slamming into the southern cities sent people running from tents to bomb shelters.

The street protest that Saturday night took the form of a silent torchlight march, with participants adopting slogans like “There is no personal security without social security.”

But many Israelis were upset with some of the young leaders who suggested that the Israeli government would try to exploit the pain of the attack victims to subvert the protests. Only about 25,000 protesters around the country participated last Saturday.

Another source of tension has arisen over the refusal by founders of the movement to cooperate with a government-appointed committee on socioeconomic change led by Manuel Trajtenberg, a respected professor of economics. Last week, Daphni Leef, who first had the idea of pitching a tent near Rothschild Boulevard and invited friends to join her on Facebook, called on Professor Trajtenberg to resign from the committee, so as not to be party to “governmental deception.”

But Itzik Shmuli, the chairman of the National Union of Students, which joined the cry for social justice early and gave it a significant lift, has supported an approach that combines protest with dialogue.

There has been growing criticism of the founders like Ms. Shaffir and Ms. Leef, part of a group of a half-dozen leaders, referred to by opponents as the “Rothschild clique.” Their demands are seen by many as excessively vague, naïve and sweeping.

“The leaders of the protest will not agree to a thing, to any sensible solution that takes into account the limitations of the economy and the global crisis,” wrote Nehemia Shtrasler, a commentator on economics, in the newspaper Haaretz on Tuesday. “Fortunately,” he added, “unlike Leef, Trajtenberg has a few hours of economics studies under his belt.”

Yet Professor Trajtenberg defended the leaders on Wednesday. “They are not professional leaders,” he said. “How would they know how to lead a perfect protest?”

Despite the griping, and regardless of the turnout this Saturday night, many Israelis say that something has changed: the public has found a voice and is not about to lose it again.

“We, as citizens, are changing,” said Ms. Doron, the singer. “It is our responsibility to be aware and to shout when something is wrong.”