New Zealand’s prime minister has defended the removal of the Māori language from an official invitation sent to an Australian government minister by saying “in my dealings with Australians it always pays to be incredibly simple”.

But the Australian minister was quick to hit back, saying he was familiar with the language thanks to the popular New Zealand band Split Enz.

The New Zealand National party leader Christopher Luxon’s comment, during question time in parliament, came in response to questioning from the Labour opposition leader, Chris Hipkins, about the government’s use of the Māori language, known as te reo Māori.

This week the broadcasters TVNZ revealed that the culture minister, Paul Goldsmith, had instructed officials to remove several te reo expressions from an invitation to Matariki, the annual celebrations of the Māori new year.

The invitation was bound for Tony Burke, Australia’s minister for multicultural affairs.

The Māori words included the greeting “tena koe” (meaning hello), the sign-off “nāku noa, nā” (which became ‘yours sincerely’), and the removal of the widely accepted Māori name for New Zealand: Aotearoa.

Goldsmith said he didn’t think Burke would know what Aotearoa meant.

“It’s hardly the scandal of the century,” he said. “I just didn’t think it needed a lot of te reo in it … I thought, let’s just keep it simple.”

But Luxon didn’t take into account the power of Split Enz educating a 13-year-old Burke in Strathfield, Sydney.

“I learnt the word [Aotearoa] in 1982 thanks to Split Enz including a reference in the lyrics, Six Months in a Leaky Boat,” Burke said on Thursday.

The hit peaked at No 2 in the Australian charts that year and was the 18th biggest song overall, sandwiched between Bananarama’s Shy Boy and Our Lips Are Sealed by the Go-Go’s.

The lyrics include the line: “Aotearoa, rugged individual / Glisten like a pearl / At the bottom of the world.”

Te reo is an official language of New Zealand, along with sign language andEnglish, and is increasingly spoken by Māori after decades of decline – in part due to hostile government policies.

Luxon’s right-leaning coalition – of the conservative National party, the free-market libertarians ACT and the populist NZ First parties – has reduced its use in government since taking office last November.

The government has issued edicts to public servants to stop communicating in te reo, and asked government departments to rebadge with English names, scrapping or de-prioritising the Māori names given more prominence during Jacinda Ardern’s government.

Goldmsith’s instruction to remove the Māori greetings – which are commonplace in New Zealand – drew criticism from Labour, particularly given it was correspondence relating to Matariki, New Zealand’s sole Indigenous public holiday.

“It’s just a shameful act … it’s an insult, not just to Māori people but to this country,” the opposition Māori development spokesperson Willie Jackson told TVNZ. “Here we are trying to celebrate this language and you’ve got a minister acting contrary to that.”

In parliament on Wednesday, Hipkins included Goldsmith’s letter in a line of questioning to Luxon on ministerial standards.

“Well, I would just say to that member, we value te reo in this government,” Luxon said.

“The correspondence was being directed to an Australian minister overseas and what I’d say to you in my dealings with Australians, it always pays to be incredibly simple and clear and use English.”

The quip recalled the former NZ leader Robert Muldoon’s infamous line that New Zealanders leaving for Australia “raised the IQ of both countries”.

But Luxon’s comment fell flat in parliament, with the foreign minister, Winston Peters, showing indifference and other MPs gasping or sounding notes of outrage.

Asked about Luxon’s sledge, the Australian prime minister, Anthony Albanese, said the conservative leader “is a friend of mine” but there were issues with communication from time to time.

“I often think that while we both speak English, sometimes we need interpreters,” he said.

“It’s the Kiwi accent. From time to time, things can be missed between us, that was the case with [former NZ prime ministers] Chris Hipkins and Jacnita Ardern before him.

“We are great friends. Sometimes we do speak a different language.”

Luxon lived in Sydney for five years during his pre-politics corporate career with Unilever.

His son, Will, is an Australian citizen, and his daughter, Olivia, graduated from the University of Melbourne last year.

“I love Australia,” he said in a 2022 interview. “If I couldn’t be a Kiwi I’d be an Aussie. Absolutely. I just love the confidence and optimism of the joint.”

It is not Luxon’s first Māori language-related misstep. In December he told public servants that wished to learn te reo they should pay for it themselves – though it was later revealed he had charged taxpayers more than NZ$3,000 for his own private tuition.