The geographical division in the front-runners' support bases must be overcome by a strong vote to elect a mayor with a city-wide mandate for progress.

In just two weeks, the long grind will be over for John Banks and Len Brown. Auckland will have its first super mayor.

Despite their perpetual campaign for the role, which seems to have run since the last local body elections, what the two men do in the next few days will define their careers.

They are locked within a couple of percentage points of each other in the Herald Digipoll survey, but are winning support in different parts of the city and at wildly varying rates.

It is not so much now what they say but what they do to get Aucklanders to vote. With the postal voting papers sitting idly on benches and kitchen tables throughout the region, the two campaign teams must work out how to stimulate the turnout to their advantage.

For Mr Brown, his opinion poll trump card is unsurprisingly among the voters of his existing city, Manukau. He has an edge in Waitakere, but is well behind in Auckland and the North Shore. He needs westies and southsiders to vote for him in such huge numbers that their turnout will swamp the twin cities and smaller council districts which the pollsters say favour John Banks.

Conversely, Mr Banks needs to inspire those on the Shore and central Auckland to get those orange voting envelopes into the post boxes, and bolster some residual support in Rodney, Papakura and Franklin to hold off a surge from the Brown stronghold.

Like any democrat, Mr Banks will want all Aucklanders to exercise their franchise, but he won't be put out if the people of Manukau have better things to do with their time over the next two weeks.

Mr Brown has the support of the Labour Party and with it the organisational advantages delivered by the union movement. People in Manukau households should expect visits from Brown's army offering every encouragement to vote, and aiming to mobilise a majority from that city that lifts their man to overall victory.

Labour, and indirectly Mr Brown, will be cursing the electoral roll-stacking in Papatoetoe that has prompted a police investigation.

For whatever reason, someone wanted to bolster numbers "eligible" to vote from at least two addresses and officers involved in the inquiry have called at two premises with links to the local Labour campaign.

No matter how important an increased turnout might be, no legitimate campaign needs help like that.

The leading candidates have defined the choice: a drier, harder recipe of "affordable progress", low rates increases and "strong, can-do" leadership from Mr Banks, or the softer, "inclusive" leadership with spending on public transport projects and focus on communities from Mr Brown.

The geographic split is predictable but unfortunate.

The Super City was devised to overcome internal borders and provide region-wide leadership that might appeal to, and deliver for, all corners of Auckland.

If residents vote only for what a candidate might do for their district a wider public benefit might be lost.

Mr Brown might well have much to offer communities in the current Auckland City, and Mr Banks' fiscal caution could be important for Manukau households.

The best result for Auckland will be if the distortions of the city's geography are overwhelmed by a strong turnout from all parts of the Super City, delivering a mandate for progress, not a last gasp display of sectoral loyalties or apathy.