Don Brash has made a scathing statement about the use of Te Reo on RNZ.
The former National Party leader said he's "utterly sick" of people using Aotearoa's indigenous language - one of its three official languages - "in what are primarily English-language broadcasts".
Mr Brash, who if often critical of the place of Māori culture in New Zealand, said Morning Report host Guyon Espiner is the "worst offender" and not one listener in hundreds "has any knowledge of what he is talking about".
Emma Espiner, who is married to RNZ host Guyon Espiner, has hit back at Mr Brash.
She wrote there are "sustained attempts" to fight against the use of Te Reo on RNZ including through BSA complaints and letters to managers, CEOs and the board.
Ms Espiner wrote in a Newsroom opinion piece that the people who are complaining about the use of Te Reo probably feel threatened by it.
"These are people who look like them, in spaces which they feel entitled to, doing something that they can't fathom," she said.
Ms Espiner said she has hope for the future of the language, despite the vocal complaints.
"As society shifts, they will continue to yap at our heels and protest, but the trend for Aotearoa is against bland mono-culturalism and fearful mono-lingualism."
She said that in ten years' time, using Te Reo on RNZ and breakfast television "will be completely normal".
Ms Espiner also pointed out that part of RNZ's charter is to reflect New Zealand's cultural identity, including Māori language and culture.
The Opportunities Party (TOP) leader Gareth Morgan has also voiced his support for RNZ and Guyon Espiner.
"I think the effort Guyon is putting in here with Te Reo is just awesome, very humbling for those of us that 'get' the bicultural nature of NZ but haven't invested (yet) in our other language. My grandchildren are my strongest role models. Go Guyon," he said on Twitter.
TOP supports making Te Reo compulsory in New Zealand schools.