Pom or Pommie ie -- Prisoner Of Mother England-- -- it harks back to Australia being a convict colony. After they lost the war with America and couldn’t send convicts there
British convicts were sent to the American colonies, such as the Province of Georgia, as cheap labour. The transportation of convicts from the United Kingdom began around 1615 and became increasingly common in the following years. Initially most people were transported to North America or the West Indies. From 1718 onwards transportation was entirely to North America. The arrangements ceased when the War of Independence meant it was no longer possible for the United Kingdom to send convicts to North America.The British Government then looked to the newly discovered east coast of Australia to use as a penal colony. Convicts were transported to Australia in 1787, arriving in Botany Bay, then Sydney Cove, in January 1788. From the very start of European settlement convicts were used as indentured labourers in five out of the six colonies. Many were used on public works, but a significant number were "assigned" to private individuals as domestic servants, rural workers, etc. Transportation was progressively abolished from 1853, eventually ceasing altogether in 1868.

AND we are still a colony but indepedant .
Hopefully Australia will become a republic but can't see it happening until the present queen dies