Sir Humphrey: When you wish to suggest that somebody is perhaps not the ideal choice...
Bernard Woolley: ...you rubbish them?
Sir Humphrey: No, the first stage is to express absolute support.
Bernard Woolley: Why?
Sir Humphrey: Because you don't want to go on record as saying somebody is no good. You must be seen to be their friend. After all, it is necessary to get behind someone before you can stab them in the back.