Auckland mayoral candidate John Tamihere is being slammed for using the words "sieg heil" during a heated political debate with Phil Goff.

A 20 second excerpt of the conversation circulating on Twitter shows Tamihere responding to Goff's comment about enjoying Auckland for its multiculturalism with the words "I say sieg heil to that".

"I love this city for its diversity 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," Goff says.

Host Martin Bradbury then asks Tamihere what he wishes for the grandchildren of Auckland to which he replies "I say sieg heil to that".

When asked by the Herald this afternoon what he meant by using those words, Tamihere said he was calling Goff a dictator.

"Because he's a dictator. You go through the whole debate, it's in the context of a heated debate. You got to be very careful about having Phil Goff as a chief censor on how people can think, what they can say, where the can say it and all of it, that was the context of the issue of the banning of those Canadians coming to speak in Auckland.

Last night at the latest Auckland Mayoral Politics Pub debate at Chapel Bar @phil_goff gave an impassioned speech about the importance of diversity in Auckland.

John Tamihere responded with the Nazi slogan "Sieg Heil".🤦‍♂️ pic.twitter.com/dHjoXtl15f

— Ryan Mearns (@ryanmearns) September 17, 2019

"I think Aucklanders and Kiwis are grown up enough to determine who they can listen to and why and that we would as New Zealanders give them the opprobrium they justly deserve, but here's the thing. Who determines whether you can think something, speak something and engage in something and who says that it's hate speech?"

Tamihere said he didn't agree with what controversial couple Stefan Molyneux and Lauren Southern were saying, but it wasn't up to him to decide whether to let them into the country or not.

Molyneux and Southern are known for holding far-right views on immigration, feminism and Islam, and were initially due to speak at the Bruce Mason Centre on Auckland's North Shore last year.

However, the event was later cancelled due to "security concerns around the health and safety of the presenters, staff and patrons".

At the time Goff said they were not welcome to use city-owned venues, leading to court action by a pro free speech group.

When contacted, Goff said he was shocked by Tamihere's choice of words and wasn't sure what he meant by them.

When told it was in the context of the Molyneux debate, he said he didn't have the power to ban them from the country and it wasn't a decision that he could make.

However, he stood by his comments at the time that he opposed what they were wanting to say.

Former Prime Minister Helen Clark, who ejected Tamihere from Cabinet while she was in office, said his comment was "appalling".