The flat lowlands around Dunkirk are changing. Motorists zooming along the A16 highway that links Paris with France’s northernmost coastline can see towering cranes and vast, newly erected, gray walls on the outskirts of the port city.

The flagship €1.5 billion ($1.6 billion) gigafactory being built by French startup Verkor is part of President Emmanuel Macron’s plan to transform an area devastated by industrial decline into Europe’s largest hub for electric-vehicle batteries. Low-carbon businesses are expected to create 20,000 local jobs in the next decade.

Macron has called the hub an example of a "thing that works.” Yet his efforts to showcase his green reindustrialization push are failing to convince voters ahead of this week’s European Parliament elections in a region that has become a stronghold for the far-right National Rally party of Marine Le Pen.