Where It All Goes Down
Dystopian England
It isn't too hard to pinpoint the setting of The Wanting Seed, because even though some boundary limits have been altered, the place is still recognizably England. Specifically, Beatrice-Joanna and Tristram live in Brighton—a seaport town on the southeast coast of England that stares straight on into the English Channel, smack dab between the North and Celtic Seas.
Recognizing the novel's dystopian setting is all in the details. In 1962, when The Wanting Seed was first published, Brighton wasn't packed full of forty-story skyscrapers built to hold a teeming population—in fact, the town doesn't even look like that today. In the world of the novel, though, overpopulation has resulted in extremely tight living conditions for everyone, which is why Beatrice-Joanna and Tristram's entire apartment could fit into Donald Trump's foyer.
In fact, given the fact that Beatrice-Joanna and Tristram tend to refer to both Brighton and London as the same place, we can infer that in the England of The Wanting Seed, the dense, over-populated urban core that London represents has spread all the way down to the coast, swallowing Brighton up into the territories of "London" itself.
Factor in a repressive government, a global food shortage, two violent police forces, a corrupt national army, and a well-oiled propaganda machine, and what you've got is a perfect recipe for a grim vision of what England might someday be.