What are '15-minute cities' being opposed in the UK?

The '15-minute city' model aims at redesigning cities so people can access all their needs like schools, clinics, or parks, within a 15-minute walk or bike ride. The UK government has called it an "anti-driver" scheme that "aggressively restricts where people can drive". Online conspiracy theories claim '15-minute cities' are designed to control population and trap people in their homes.