Actions of Governments in Exile
International law recognizes that governments in exile may undertake many types of actions in the conduct of their daily affairs. These actions include:
becoming a party to a bilateral or international treaty
maintaining military forces
amending or revising its own constitution
retaining (or "newly obtaining' diplomatic recognition by sovereign states
issuing identity cards
allowing the formation of new political parties
holding elections
allowing for direct (more broadly based) elections of its government officers etc.
However, none of these actions can serve to legitimize a government in exile to become the internationally recognized legal government of its current locality. By definition, a government in exile is spoken of in terms of its native country, hence it must return to its native country and regain power there in order to obtain legitimacy as the legal government of that geographic area.
Still, in cases where the host country holds a large expatriate population from a government-in-exile's home country, or a population ethnically originating from that country, the government-in-exile might come to exercise some governmental functions towards such a population.