Auckland mayoral candidate John Tamihere is defending his use of the words "sieg heil" during last night's lively political debate with Phil Goff, despite being lambasted for it on social media.

Photo: RNZ / Matthew Hutching.

A short clip of the debate circulating on Twitter has already been seen by thousands of people, showing Mr Tamihere's response to Auckland mayor Phil Goff speaking on diversity at a pub politics debate in Ponsonby on Tuesday night.

Mr Goff said he would like his grandchildren to grow up in a diverse city "and we won't put up with the sort of nonsense that we get from racists coming into this country to tell us that multiculturalism doesn't work".

"In six weeks time I've got a grandson that will be born that's a quarter Māori, a quarter Filipino, and a quarter Irish and a quarter English, and I'll be really proud of that kid. That kid will represent the future of our city," Mr Goff said.

The video shows Mr Tamihere started off his response: "Well, I say sieg heil to that".

I suspect even Tamihere's stoutest defenders are tiring of this idiocy. https://t.co/vedeB7JuiS — Russell Brown (@publicaddress) September 17, 2019

People have expressed concern at the use of the phrase associated with Nazis and former Prime Minister Helen Clark has waded into the ring calling the use of the Nazi slogan "appalling" on Twitter.

But Mr Tamihere has defended his use of the phrase in the context of the debate.

"Mr Goff was very strong on ensuring anyone that doesn't agree with him that he takes objection to, that he can suppress them coming into Auckland or using Auckland community facilities to host events, I'm talking about the two Canadians," Mr Tamihere said.

Controversial Canadian speakers Lauren Southern and Stefan Molyneux were banned from speaking at an Auckland Council venue last year.

"My own view on it is that that is incorrect, that whilst I might vehemently oppose them the best disinfectant is daylight and to suppress them is to then determine that you're a dictator on what people can think or say."

Asked by RNZ if he was likening Mr Goff to Hitler, Mr Tamihere said:

"The analogy is about a dictator, what dictator would you choose?

"Because Hitler was a terrible person who was a dictator and wanted to determine who could speak, when they could speak and what they could say. Very simple analogy in a debate. When you're in the heat of a debate that's what happens."

He said the debate was fierce and called the video circulating on social media a "cut and paste".

"I don't need to think like you, I don't need to act like you and that's the whole issue of this whole mayoralty," Mr Tamihere said.

"I'm allowed in a democracy to have a say without people criticising me solely because of the way in which I run my debate. End of story I would have thought."

Auckland mayor Phill Goff said he was "astonished" Mr Tamihere was defending his choice of words

"I don't know where it came from and I really didn't believe that he has just said that. You don't expect that from a contender for the Auckland mayoralty, one of the diverse cities in the world, and almost six months to the day after the Christchurch terrorist attack," Mr Goff said.

Mr Goff said it will remind people that Mr Tamihere has said many insulting things over time.

"It's kind of sad that we should even be having this discussion that he had made that comment. I can't think of any debate that I've had over 14 elections that I've fought in that degrades to that sort of comment. It's not right."

Mr Goff said he was not expecting an apology from Mr Tamihere, even though it would be nice.

The Holocaust Centre of New Zealand has also condemned Mr Tamihere's comment.

Chief executive Chris Harris said in a statement: "Mr Tamihere uses Nazi language - the language of race hatred - in a throwaway manner. It is wrong, deeply irresponsible and inciting hate in one of the world's most ethnically diverse cities. It is utterly unacceptable for a public figure to evoke Hitler and the Nazis as Mr Tamihere is doing."

The centre provides education about and remembrance of the Holocaust - the genocide of European Jews and others during World War II.