Mandrake

From the author's website:
"Susan Cooper set this 1964 sci-fi thriller in an Orwellian future of 1980. England is under the power of a lunatic Prime Minister Mandrake, who creates a planned society of isolation that forces people back to their place of origin. Standing against his insanity is anthropologist Dr David Queston, an expert on man and “the tyranny of place.” England has sunk into a nightmare of destitute walled cities filled with a hysterical public overcome with fear; unexplained natural disasters add to Queston’s suspicions that the earth itself is rebelling against man’s attachment to the earth and nuclear presumptions. It is up to Queston and his fellow rootless travelers (including the beautiful actress Beth) to challenge authority and restore hope for the future."