Every nation holds one seat in the UDN. That seat belongs to whoever can claim it with the strongest electoral mandate — not by appointment, and not permanently. An electoral mandate can come from a direct vote count (e.g., a mayor) or from commanding a governing majority (e.g., a prime minister backed by parliament).
Most seats are initially held by volunteers: private citizens with no electoral mandate of their own, representing their nation as a way of seeding the process. From there the UDN continues to gain legitimacy as individuals with a stronger electoral mandate step forward.
If you were elected to an office and believe you hold a stronger electoral mandate than your nation's current UDN member, apply for membership below.