Kiwi MP Jamie Strange reignites trans-Tasman debate after posing whether New Zealand and Australia should become one country

An age-old trans-Tasman debate has been reignited: Should New Zealand become part of Australia?

Outgoing Kiwi MP Jamie Strange raised the idea in his valedictory speech, and former Australian Deputy Prime Minister Barnaby Joyce backs it.

"We ponder the thought - will we ever become one country, Australia and New Zealand? My personal view - and it's only a personal view - is that New Zealanders shouldn't rule that out," Strange said.

He reignited an age-old debate that has struck a nerve with Kiwis.

"No, you're not seriously asking that question," said National Party leader Christopher Luxon. "No, there's no way in hell we're joining Australia."

But Strange gave us many reasons why.

"There would certainly be economic benefits, economies of scale in the private and public sector, opening ALDI stores on our shores," he said.

And Australia would get a decent rugby team.

"We might even win a rugby game, that'd be great," Joyce said.

Joyce knows what it's like to be a Kiwi. As an MP, Prime Minister Chris Hipkins uncovered a quirk in our law that made Australia's then-Deputy Prime Minister a New Zealand citizen.

Joyce said technically a merger could happen.

"We could actually bring them in without a referendum, it's actually part of the constitution now," Joyce said.

And he's right. In black and white on page six, the Commonwealth of Australia lists all its states, including New Zealand.

But if you're starting to worry you'll have to support the Wallabies this World Cup, don't.

"This isn't the first time that Barnaby Joyce has been confused about Australia and New Zealand being different countries," said Australia Prime Minister Anthony Albanese.