The Professional Firefighters Union wants rural and city firefighters to join forces saying the country isn't big enough to have two separate operations.
It said the Fire Service needs more funding, and the services should amalgamate under a single national commander.
Submissions on a Government review of the Fire Service closed on Friday.
The service is currently funded through an insurance levy and the Government has ruled out funding it from general taxation.
The Union's secretary, Derek Best, said many services it provided were free.
He said a large amount of Government-owned property wasn't insured, so no levy was paid.
"The levy could be expanded from just general property insurance or other sorts of insurance," he said.
"Government departments that do not insure their own property, like Housing New Zealand and so on, could be required to make a contribution.
"There could be additional charges on motor vehicle registration to pay for motor vehicle accidents."