Auckland councillors will not only formally censure Mr Brown but begin a process designed to clip the wings of the mayoral office. If that happens, the Super City may no longer have a leader with the independent authority to drive things forward.
So according the the mouthpiece of big business, Auckland's mayor must go lest its mayoralty become more democratic. And then they wonder why we think they're all authoritarians...
Meanwhile, the right-wing faction of the Auckland Council are going for a formal no-confidence motion. Legally, this has no effect - the mayor is elected, not appointed, and is not dependent on the continuing confidence of the council to hold office. But symbolically, its huge. And if reinforced by a commitment from those supporting it to block every mayoral initiative, then Brown's position becomes absolutely untenable. While legally it would have no effect, practically it would mean he had to resign (the same applies to the various other options, such as oversight committees etc being proposed: if the Council backs them with a credible threat to block everything unless accepted, then the mayor's formal powers become subject to the Council).
If this seems like a familiar story, its because it is: it's exactly how we got responsible government, AKA Ministers responsible to the elected Parliament (and hence us) rather than the unelected monarch. The dependence of Prime Ministers on Parliament to legislate and vote suppy for their policies gave the latter leverage to ultimately control their appointment (hence, the constitutional convention that the monarch appoints the person with the confidence of the House as Prime Minister - because otherwise, she gets one who can't do anything, and possibly we cut off her sock budget as well). It played out in the UK, it is currently playing out in the EU (where the elected European Parliament is asserting control over the unelected Commission) and in Tonga, and now its happening in Auckland. And the result may be our first "responsible mayor".
But if Auckland's mayor is going to be responsible to the council, and forced to resign if the council refuses them a majority, it inevitably invites the question: why elect them separately? We're not there yet, but all it will take is a mayor and council of opposite political persuasions, and then the real fun will begin.