Perhaps surprisingly, whistleblowers are relatively common in large corporations. Some are fantasists, others harbour deep personal grudges against the company or executive they work for; some raise legitimate, though in the scale of things, relatively trivial concerns, others are simply looking for a pay-off. Just occasionally, they blow the lid on some major scandal.

I may have to eat my words, but I doubt very much if the whistleblower said to be behind the WPP board’s decision to investigate Sir Martin Sorrell for alleged “personal misconduct” falls into the latter category.

It is impossible to believe that a chief executive as savvy and seasoned as Sir Martin could have been guilty of something...