BASS Labor MHR Jodie Campbell's chief of staff Emma Brindley will leave at the end of the month.
Ms Brindley said she was returning to Sydney to be with her fiancee and would take up a similar position with a NSW state MP.
It is uncertain whether Ms Campbell will replace Ms Brindley, given that she is not re-contesting her seat at the next federal election which is only months away.
Ms Brindley is the fourth staff member to leave the MHR's office since January last year.