Residents of Potters Bar, a small town just north of London, are trying to block what would be one of Europe's largest data centers from being built on 85 acres of rolling farmland that separates their community from the neighboring village of South Mimms. Multinational operator Equinix acquired the land last October after the local council granted planning permission in January 2025, and the company intends to break ground this year on a development it estimates will cost more than $5 billion.

The UK government's decision to classify data centers as "critical national infrastructure" and a new "gray belt" land designation that loosens building restrictions on underperforming greenbelt par...