shadow government

noun2

1. •
   A government that is prepared to take control in response to certain events, especially one made up of the leadership of the largest opposition party in parliament which would assume control should the ruling party be displaced in elections.

   • Cuba's two most important exile groups, after months of quarreling, met last week to form a shadow government dedicated to the liberation of their homeland. — 1961
2. •
   A (real or conspiracy theorized) body of private individuals who exercise actual power behind the scenes instead of a country's or organization's public figures.