Senior U.K. ministers are hardly paupers, but by the standards of high-flying private sector jobs, they don’t exactly rake it in. That’s why it’s called public service.

Power has its own perks, however. Many former top-tier public officials soon make up the gap in earnings after they leave office.

Writing a memoir, collecting speaking fees and serving on a few blue-chip boards are the usual post-government income streams. Those sorts of earners — largely trading on experience, celebrity and knowledge — are priced into the job and seem a fair reward for the pressures and responsibilities (yes, it is also a tremendous privilege) of high public office.