At times since the Tax Working Group batted out a proposal for a comprehensive capital gains tax, both Prime Minister Jacinda Ardern and Finance Minister Grant Robertson have wished for the impossible.

They have called for the Opposition to dial back the hyperbole and stop scaremongering.

Instead, they say, National should take part in some "reasoned debate" with the rest of New Zealand.


Good luck with that.

Week One of the debate was spent analysing what the "Kiwi way of life" Simon Bridges had spoken of actually meant. There were many worthy spoofs and memes created in the pursuit of this.

But by Week Two, whatever people thought of the Kiwi way of life, Ardern was clearly worried enough the line was getting traction to try to front foot the issue.

Ardern spent the bulk of one press conference trying to deflect National's attacks. The one she identified as particularly hyperbolic was the Kiwi way of life one.

There are many weeks to go.

The two-month gap between the Tax Working Group reporting back and the Government response to it provides plenty of time for scaremongering in itself.

That gap in itself is a mistake, for time allows uncertainty to thrive.

Ardern needs to stamp out that uncertainty as soon as possible but finding some consensus between Labour, NZ First and the Greens may be just as impossible as wishing National would shut up.

That means any consensus will also be fragile. Someone will be more peeved than the others.

Bridges grills PM on small business experience.

It also means Ardern's headache will not necessarily end once a consensus is reached and the legislation put in place.


She will also have to convince voters that no further changes will take place after 2020, without knowing exactly what price she might have to pay to get the government benches back.

So the big question is how vulnerable that "certainty" will be to an election campaign and post-election negotiations.

If the consensus position is a pale imitation of a capital gains tax, Ardern and Labour would not be barred from campaigning on a Labour Party policy – rather than a government policy – for a broader tax.

It would be foolish to do so and Ardern will have no appetite for that, even if it means effectively ceding a long-held policy position to NZ First.

She will promise to go as far as the parties agree and no further.

But Ardern cannot hog-tie NZ First and the Green Party to that.

Either or both of those parties can go into the campaign pushing for a narrower or broader regime - and both will be looking for ways to differentiate themselves.

That gives National a window to argue that the "certainty" Ardern has promised is a fake one, for Ardern cannot guarantee it will not come a cropper in post-election talks.

PM Jacinda Ardern and NZ First leader Winston Peters in 2017. Photo / Mark Mitchell
PM Jacinda Ardern and NZ First leader Winston Peters in 2017. Photo / Mark Mitchell

In that regard, the best-case scenario for Ardern post-2020 is the clowns to the left of her, jokers to the right scenario.

That is for Labour to be able to form a majority with either NZ First or the Greens – rather than needing both, as it does now.

In that case, neither will have the power they have now.

The worst case (other than losing to National) is if one of those support parties does not make it back in and the other has all the power.

Thus far, the Greens have called for a broad capital gains tax. NZ First could be convinced to support one that targets the likes of land bankers and property speculators, but are wary of creating an accountant's paradise by going much further.

NZ First will likely win. But should that much-diluted package be agreed on, Ardern will stand accused of failing to deliver on the "change" she promised in the campaign.

National has many, many weeks of fun ahead regardless of what the Government comes back with.

They will use it. When it comes to hyperbole, Labour used exactly the same tricks on National when it campaigned on asset sales in 2011 – another policy considered unpalatable.

As National showed with asset sales, there is a small window of opportunity for leaders to expend political capital. Ardern risks losing that window.