Between abandoned coal mines and an engine plant scheduled for closure, a gleaming new factory hovers like a phoenix over Billy-Berclau, a small industrial town in northern France. Inside, 700 newly hired workers are making next-generation electric vehicle batteries for the Automotive Cells Company — part of a grand project to revive the wider region’s flailing fortunes.

A “Battery Valley” is rising here from the remains of industries that shuttered during a wave of globalization. Three more giant electric car battery plants are expected to open by 2026, a testament to a re-industrialization strategy that President Emmanuel Macron’s government has trumpeted as an antidote to the far-right National Rally party, which has gained ground in areas decimated by job losses.

“Industry is an anti-National Rally weapon, because in places where anger has risen, we’re restoring hope,” Roland Lescure, Mr. Macron’s deputy industry minister, said earlier this year.

But the bet is not paying off politically. Billy-Berclau, and nearly every other town in this region of Pas-de-Calais handed a resounding victory last week to National Rally in parliamentary elections — a trend that is likely to be repeated in a final voting round on Sunday.

“There’s a sense of disconnect,” said André Kuchcinski, president of the Artois-Flandres Industrial Park, an area covering more than 1,100 acres where Automotive Cells Company, known as ACC, is expanding its new plant. “You have a government that pushed for development and job creation, but a lot of people are still struggling and feel insecure,” he said. “A new factory doesn’t address that, but there’s a feeling that the far right does.”

Around Billy-Berclau, people speak in hushed tones of a political earthquake coming.

“There used to be thousands of more jobs. The new factory only makes up a fraction of the ones lost,” said Marc Vandamme, 54, a home care nurse, sipping a beer at the Europe Cafe, a local hangout where people buy lottery tickets or down a coffee before work.