Super City mayoral candidate Len Brown has considered pulling out of the race because of the impact on his family, he has revealed in an emotional interview.

He said only Jesus Christ had withstood such a high level of scrutiny as him, and come out clean. If ratepayers demand that he identifies who he meets with, then he will quit as Manukau mayor.

Brown spoke with the Herald on Sunday after the Auditor-General chastened him for "mistakes" but decided not to further investigate personal spending on his city council credit card.

The mayor insisted he had no obligation to disclose who he had taken to dinner on public money, and that criticism of his spending was a Citizens and Ratepayers "smear campaign".

"It hurts my family and it hurts my friends," he said, tears welling in his eyes. "I have got three daughters and two are still at home and they have friends. The youngies in particular find it really difficult - we are trying to shelter them."

His daughters are Samantha, 21, Olivia, 13, and Victoria, 11. Becoming emotional again, he said: "They understand, but the real cost of politics is not mayoralty expenses - it's the cost on your family."

Asked if he ever wanted to give up, he said: "Absolutely. It is a very high price to pay for wanting to achieve something better in life."

Brown has come under fire for personal purchases including a $148 mini hi-fi system and a $59 Christmas ham, bought with the council credit card.

He later refunded both purchases from his own pocket.

And he has utterly refused to identify who he and mayoress Shan Inglis hosted at their table for an $810 fundraiser dinner at Volare restaurant in Manurewa.

He had good reasons for refusing to identify his guests, he said.

"It is against my principles. I am fighting back on what I believe are the key issues of this campaign and what people are vitally interested in."

He shouted: "I clearly don't give a damn about this stuff."

"It's critical for me as a point of basic principle as a leader and mayor of the city.

"I sit in this room. I don't tell anybody I am having an interview with you today. It is between you and me. It is totally confidential."

He said there was no requirement for him to disclose who he spent council money on.

"Transparency is not a perfect thing," he added.

"Transparency doesn't just happen in a perfect world. You have to measure that up against other significant principles and that's what I'm doing and I will live or die on that.

"If people make a judgment and say, 'we all agree you should tell everybody who you are seeing all the time', then I'll say, 'that's it - I am not the mayor any more'.

"If you ask me, do you have good office management around your credit card, clearly not brilliant but not worse than some, I can tell you. I am not running to be office manager."

Inglis supported his secrecy around his guests at the dinner. "I can say, it was a business function. There was nothing personal about the dinner. There were no family members there at all - none."

She said the couple and their children had talked through his decision to run for mayor of the Supercity.

"Len already works long hours - he is away a lot - and we have talked about these issues. But I think many of those challenges are well thought out. He hasn't taken this decision lightly."

Brown added: "I'm under extraordinary scrutiny and maybe Jesus Christ was the only one to withstand that and come out completely pure."

The world according to Len Brown
What drives him: "I have an open heart for this work. I believe I have a contribution to make. I believe I can be the glue in the sticking of Auckland together."

Was the face-slapping plea for forgiveness a bit over the top? "I am a passionate politician. People connect with me because they can see, feel and hear my passion and the love for them."

On multiculturalism, rapping and singing: "I learn languages reasonably well so I can relate and I sing songs. I am really busy working on a Chinese song - so look out."

On reaching out to greater Auckland: "I will be over in Mt Eden, Titirangi, Takapuna, Pukekohe - I am going to be over these places like a rash ... I love you Mt Eden."

On why voters should trust him: "I will always front up. I will give you the straight answers, always with a limit."