Citizenship changes for New Zealanders in Australia could lead to a greater strain on housing and the welfare system, the opposition has warned.
The coalition's immigration spokesman Dan Tehan has questioned the government on the cost of the citizenship changes.
Almost 400,000 Kiwis living in Australia will be able to become citizens without needing to become permanent residents, following a deal struck between Prime Minister Anthony Albanese and his New Zealand counterpart Chris Hipkins.
The changes, which has restored reciprocal rights for citizens of the two countries, will kick in from July.
Mr Tehan said while he agreed with the citizenship reforms in principle, he still had some concerns.
"They are changing what has been rules that have been put in place for a long time and we want to know what the costs will be," he told ABC TV on Monday.
"Over time, we might see New Zealand citizens come in here to access our welfare system - that has a cost."
Mr Tehan also questioned whether the citizenship changes would impact on the government's annual migration cap, and if it needed to be adjusted as a result.
He said the greater number of people accessing systems could also place pressure on housing.
"We're seeing soaring rents, there's a housing crisis at the moment. So additional New Zealanders come in here because of these changes, what impact will it have on our housing shortages at the moment?" Mr Tehan said.
Kiwis in Australia prior to 2001 were able to gain automatic permanent residency, but changes made in 2001 by the Howard government placed new arrivals in a special visa category.
The category limited access to services such as Medicare or welfare payments, with New Zealand advocates campaigning for years for the return of the reciprocal arrangements.
"One of the reasons that the current arrangements were put in place is because we have a much more generous welfare system here in Australia than they do in New Zealand," Mr Tehan said.
Under the changes, children of New Zealanders born in Australia will also become citizens at birth, rather than waiting until they are 10.
Mr Albanese said the changes would lead to a fairer and more inclusive migration system.
"Australia and New Zealand have a deep friendship, which has been forged through our history, shared values and common outlook," he said on Saturday.
"I am proud to offer the benefits that citizenship provides."
Mr Hipkins said on the weekend it would ease pressure on his government's budget.
"If we're looking at it on an issue of fairness, the main thing that accessing Australian citizenship will do for those Kiwis is that will allow them to access public services that they have otherwise been denied access to," he said.
"That's better for New Zealand because in the absence of being able to access Australian public services, the fallback position was New Zealand public services which they ultimately weren't contributing towards because their taxes were being paid here in Australia."
