government-in-exile

A government in exile is a political group that claims to be a country's legitimate government, but for various reasons is unable to exercise its legal power, and instead resides in a foreign country. Governments in exile usually operate under the assumption that they will one day return to their native country and regain power.
See more at Wikipedia.org...

Noun
1. a temporary government moved to or formed in a foreign land by exiles who hope to rule when their country is liberated
(hypernym) government, authorities, regime