“If you kick an angry dog, he’ll bite you and he won’t let go,” said Alain Giménez, a community leader, as others who had gathered in the raffish Place du Puig, or “Hill Square” in the local Catalan, nodded their assent.

“So, what are we here, nothing? They say we’re dirty,” said Mr. Giménez, who calls himself “Nounourse,” or teddy bear, mocking his own portliness. “The problem is, they don’t talk to us, they just say we are dirty.”

The truce achieved with the city over the demolitions is only temporary, said Jean-Bernard Mathon, head of the local preservation society. At least 37 more buildings in Saint Jacques were slated to come down, he said.

“What we want is the rehabilitation of the old core,” Mr. Mathon said. “What they want to do is demolish. But they have rebuilt nothing. It’s hideous.”

Saint Jacques, dilapidated, crumbling and now threatened, even drew the backing of President Emmanuel Macron’s special emissary on historical preservation, the French television personality, Stéphane Bern.

Mr. Bern wrote on social media that he was “scandalized and shocked by the images of destruction in the center of Perpignan,” and promised his “support and solidarity.”