What is the origin of the idiom "chattering class" and when to use it?

The idiom "chattering class" is believed to have originated in the late 20th century, specifically in the United Kingdom. It gained prominence in the 1980s and 1990s as a term used to describe a particular group of individuals who were seen as excessively talkative and opinionated, particularly in the realm of politics and media. The phrase is used to convey a sense of criticism or annoyance with this group, suggesting that they are more focused on talk and debate rather than taking practical action or effecting meaningful change.