What is the origin of the idiom "the gnomes of Zurich" and when to use it?

The origin of the phrase "the gnomes of Zurich" can be traced back to the 1960s. The phrase was popularized by a British politician named Harold Wilson, who used it in a speech in 1964 to criticize the role that Swiss bankers were playing in international finance. The phrase "the gnomes of Zurich" is primarily associated with Swiss bankers and financiers, given the historical context in which the term first emerged. However, the phrase can also be used more generally to refer to powerful and secretive figures in the world of finance who are thought to be manipulating the global financial system for their own gain.