The author calls for some type of regulation on supermarkets or "the control of food supply". For example rules that chain stores provide evidence they are appropriate for the income level of the neighborhood, as in San Francisco.
"Until then, the food supply of UK cities – and the character of our neighbourhoods – will be subject only to the law of which supermarket locations are most profitable per square foot."
This is related to the "food desert" phenomenon cropping up in the US. Haven't heard much being done on this front: https://en.wikipedia.org/wiki/Food_desert