One of the most puzzling aspects of the Len Brown scandal is when he found time to cheat on his wife, says former North Shore City mayor-turned-MP Andrew Williams.

"It was full on - from dawn to dusk," said Mr Williams, now a New Zealand First MP. "Your spare time would be limited. I am somewhat aghast he would have had the time to do it. I was run ragged for three years.

"[Wife] Jane said to me, 'I can't believe he would have time for an affair'."

Mr Williams has some familiarity with the heat on Mr Brown, having faced intense scrutiny after being filmed urinating on a tree in Takapuna.

The Whale Oil blog, which broke news of Mr Brown's affair with Bevan Chuang and demanded he resign, also sought Mr Williams' resignation.

However, while Mr Williams was embarrassed at being caught short, he said Mr Brown had created his own problems.

"He's definitely brought it upon himself. He should have seen it coming - he should have seen what was going to result from his actions."

He said Mr Brown had done "quite a good job" but was surprised he had stayed on. Mr Williams would not say outright the mayor should resign; it was up to him. He added: "I don't think he has given it enough consideration as to whether he has the moral authority to run the city."

Mr Williams said he was surprised by the details brought out in the EY (Ernst & Young) report. The amount of phone contact with Ms Chuang was a surprise. "I don't think I would have rung my wife 1375 times."

He said the frequency of stays in hotels in the city was also unusual. Mr Williams said it would have taken Mr Brown as long to get home as it used to take him as North Shore City mayor - and he had needed a hotel only once. On that single occasion, city-based meetings were followed by a black tie function and a 6.30am start the next day.

The number of stays by Mr Brown "seems excessive", particularly considering the Super City mayoralty came with a car and driver.

The SkyCity hospitality - including free rooms and upgrades - was "definitely a conflict of interest".

"That should have sent alarm bells to Len straight away."

Mr Williams said Mr Brown was on his last chance.

While he was Manukau mayor, spending irregularities before the Super City election served as a first strike, with the inquiry from the current allegations being thesecond.

"Third time and it's all over Rover."

Mr Williams said the scandal showed further weaknesses in the creation of the new Auckland local authority.

"It's just another nail in the coffin of the Super City.

"I think it's lost control in a number of areas."