John Armstrong: That ain't lipstick - it's war paint

• John Armstrong is a former New Zealand Herald political correspondent.

Make no mistake. That isn't lipstick adorning the face of Jacinda Ardern. It's war paint.

Woe betide anyone who gets in the way of Labour's Warrior Queen and the sharpened blades on the wheels of her chariot.

What probably saved Gareth Morgan from being instantly rendered into mincemeat or -perhaps more aptly - bacon rashers by her ploughing Boadicea-like into the thin ranks of his Opportunities Party is his sheer inconsequentiality in this ever-changing election campaign. It was simply not worth her bother.

More's the pity. Morgan's "lipstick on a pig" jibe was deserving of reward. To his myriad number of identities - businessman, economist, investment manager, philanthropist, motor cyclist and cat-hater - Morgan can add yet another title - that of political buffoon.

His imperious insistence that Ardern show she amounts to more than just lipstick on the Labour pig was astonishing in its ignorance of what is actually happening.

His insult is part of the lexicon utilised by Ardern's detractors to denigrate her rapid ascent to Labour's leadership as a victory of style over substance.

The accusation that Ardern is suffering from a substance deficiency is a very cheap shot.

It is being fired in her direction to hide a very uncomfortable home truth - namely that Labour's rivals seem to have little idea how to counter her extraordinary appeal.

The slur was echoed by Winston Peters in his trotting out the now-ancient quip of "where's the beef?".

Well, the beef is sizzling on high heat right in front of both him and Morgan.

Once again. Labour is trying to coax voters to acquiesce, albeit reluctantly, to fill the gaping hole in New Zealand's tax fabric resulting from the absence of a capital games tax.

Things don't get more substantial than that in domestic politics.

Given Morgan's advocacy of an assets tax, you would have assumed he had been engaged in microscopic observation of the subtle ploys required to nudge voters in that direction without offering National any opportunity to blow such reform right out of the water.

Illustration / Guy Body

The task that Ardern and Grant Robertson, her finance spokesman, have set themselves is to get the introduction of a capital gains tax acknowledged as a given should Labour win the election -but without them directly saying or confirming as much.

Given the long-assumed risks of going anywhere near this veritable mother of all minefields, you might well wonder why they have embarked on such a seeming fool's errand.

The answer is that if Labour wishes to be taken seriously when it comes to tackling wealth inequality, then a capital gains tax has to be part of its policy mix.

Labour can no longer shy away from reform - especially when poverty and homelessness has become a hugely pressing issue in this election well beyond the environs of those directly affected.

Such a tax will not result in some overnight redistribution of wealth. Far from it. But it would address the unfairness which riddles the current tax framework.

To win the argument, Ardern and Robertson must somehow turn the absence of such a tax into an example of dereliction of duty on National's part.

Above all, Ardern's promise to be bold and brave requires a capital gains tax be high on her agenda. If it isn't, then the whole edifice underpinning her leadership is undermined.
In not ruling out such a tax, she is very much ruling one in.

In doing so, she is diving into very deep and dangerous waters.

That is no doubt more preferable, however, than enduring lectures from the likes of Morgan - lectures which carry all the authority and gravitas that come from someone still wading in the ankle-high depths of the paddling pool of politics.