KEY POINTS:
Treaty issues would heavily complicate any attempt to create a common legal system between Australia and New Zealand, says a public law specialist.
The suggestion came from an Australian House of Representatives committee looking at harmonising the legal systems of both countries.
It suggested Australia and New Zealand should also consider introducing a common currency and even becoming one country.
However, Alistair Hercus, a former diplomat and now partner with New Zealand law firm Buddle Findlay, said a common legal system would be hard to sell.
"Legal union I understand to be complete union. Legal union means there is one country called Australasia or whatever you like to call it ... New Zealand ceases to a member of the United Nations, ceases to be a member of the Commonwealth, ceases to be an independent member of anything."
Mr Hercus said harmonisation of legal systems was quite different as both countries retained the right to change their laws. He said in theory it was possible to have a common legal system, but the Treaty of Waitangi would be a major sticking point, rising above mere status as a state matter.
It would also mean New Zealand would have to do a much better job of defining what the Treaty involved.
"In order to preserve the Treaty, we would have to define more clearly than we ever have before the way in which we want the Treaty to operate, in statute as distinct from a series of court decisions and the terminology and principles of the Treaty.
"And then in the new arrangements ... it would have to be in fact prohibited that the rest of Australia could somehow amend or revoke whatever arrangements we decide are appropriate in New Zealand."
However, Mr Hercus said there were more moderate steps that could make good sense for both countries.
Australia and New Zealand already had single regulators in several areas, including a joint therapeutic agency that reduced the cost of New Zealand assessing every drug.
It was also possible to go down the path of the European Union, with common borders that would make travel between New Zealand and Australia effectively a domestic journey.
The two countries could also consider common tariffs for goods and people entering the country.
A common currency was more problematic as both countries had different economic bases.
If the cost of minerals in Australia rose, it could strengthen a joint currency, making it difficult for New Zealand's export-based economy.
Mr Hercus said such proposals did not mean giving up cultural identity. The Australian committee found that while the two countries were sovereign nations, their strong ties made the possibility of a closer relationship "desirable and realistic".
- NZPA
