Shan Inglis, the lawyer wife of Auckland mayoral candidate Len Brown, has throat cancer and needs urgent treatment.

But the couple both insist that her illness will not stop Mr Brown - who has been under severe pressure in recent weeks - from running for the Super City's top job.

Ms Inglis, 49, has been diagnosed with papillary thyroid carcinoma, the most common form of thyroid cancer, which normally has a very high survival rate with treatment.

She had an exploratory operation a month ago to remove some tissue and tests revealed the cancer was present.

She will undergo an operation to remove malignant tissue and a course of radiation treatment which will keep her off work and less able to support her husband's campaign in the run-in to the October election.

Voting papers go out on September 17.

In a statement released to the Weekend Herald, the couple said the prognosis for full recovery was very positive.

They were disclosing some details of the illness to avoid speculation over Ms Inglis's upcoming absence from campaign and mayoral-related activity.

Mr Brown, 53, is Mayor of Manukau and Ms Inglis undertakes public duties as mayoress. She is a partner in the Pakuranga law firm Muller Law.

Mr Brown - who nearly died two years ago from a heart attack - said his wife had explicitly requested that he continue his campaign for the Super City mayoralty.

"We know what it is like to deal with tough family health issues, and we know that recovery is best served by taking a positive approach in which we offer Shan every support while continuing to function as close to normal as is possible."

The test results were confirmed two weeks ago just as Mr Brown was enduring sustained media scrutiny of his council credit card use.

The Herald understands he considered withdrawing from the campaign to support his wife and their children Samantha, 21, Olivia, 13, and Victoria, 11. But Ms Inglis, a close adviser on political matters, preferred a business-as-usual approach.