Former Labour Party president Mike Williams has suggested there is no need for Te Reo in prisons because it does not help inmates get a job once they are released.
Mr Williams was speaking for the New Zealand Howard League in an official capacity when he made the comments at a public discussion about prisons this week.
Māori make up more than half the country's prison population.
Mr Williams was asked by an audience member if there should be encouragement for more Māori culture and Te Reo use in New Zealand jails.
"My response is that New Zealand runs on English - and that's the reality of it - we speak English," Mr Williams replied.
Mr Williams continued, saying:
"[If] you want to go and get a job, don't bowl up speaking Māori.
"This is the reality we have to deal with... I can speak French and German but I don't try to buy a bus ticket with either of those languages."
Mr Williams' comments provoked a surprised and audible response from some in the audience at the University of Auckland, at an event organised by the JustSpeak group.
About 60 people, mainly students, were there.
Labour MP Kelvin Davis was on the panel with Mr Williams and later told Radio New Zealand he was surprised at what was said.
"I was disappointed with his comment, I know there's any number of jobs that can be had because of people's ability to speak Māori.
"In fact I'm a case in point, and I think just about every job I've got is because of my ability to speak Māori so think that his comments were poor form," Mr Davis said.
Mike Williams operates literacy programmes in prisons throughout the country.
When Radio New Zealand asked him about his comments, Mr Williams said he was not against Te Reo being used in prisons.
He said the point of his work was to raise English literacy levels so prisoners could get a driver's licence.