Prime Minister John Key said he didn't discuss Len Brown's affair when the pair had their monthly catch-up in Auckland this morning.

Speaking after a lunchtime engagement in South Auckland, Mr Key said it wasn't his place to comment on allegations Mr Brown accepted "freebies" from hotels while conducting his affair.

"All I can say is that I met with the mayor this morning, that's consistent with my monthly chats that I have with him and I pretty much stuck to business.

"It was really a discussion about the issues that we're contending with in Auckland, in particular around housing and transport."


Mr Brown's affair was "ultimately a matter between Len and his family", Mr Key said.

"Any other answers he needs to give he really needs to give to that [Auckland Council] inquiry.

"I have a good working relationship with Len Brown and I communicate with him regularly, both via text or phone and regular meetings.

"My guess would be if [he resigned], Len would probably flick me a text or give me a call, but he's not required in any way to do so."

Mr Key said Mr Brown's affair scandal was not something he wanted to "pass judgement on".

Mr Brown was due to attend the same engagment this morning and Mr Key said he understood the mayor's no-show.

"In fairness, he's dealing with the fallout of a significant issue. It's not unusual for public figures when they face various crises to go to ground a little bit.

"I certainly had a constructive meeting with him about the issues that matter this morning, but it's not unusual for people to take a little bit of time out for things to settle.

"I'm sure he'll be back on the horse as soon as he can."

Mr Key said he had not lost any confidence in Mr Brown over the affair revelations.