COMMENT:

Jacinda Ardern's got to start thinking dirty this year, as in doing electorate deals that is.

Since MMP came into being there have been three-term governments, so a second term administration would usually be a foregone conclusion.

But we're facing a volatile electorate - and Labour's going up against an opponent in National whose vote has consistently held up, with the majority of polls showing it outstripping Labour.

And for the first time under the electoral system the party with easily the strongest vote didn't get to occupy the Treasury benches, Winston Peters (injured by the former leadership) saw to that. In his book the current leadership is just as toxic.

Given what happened after the last election, Ardern can't afford to become comfortable with the precedent of three-term MMP governments. Precedent was blown out of the water by Peters going with Labour over National, given it scored 44 per cent of the vote to Labour's 37, or almost 200,000 more votes than Labour.

The coming months will require some serious strategic thinking.

Simon Bridges knows that if he declares his hand, as John Key did in 2008, and rules out working with Peters it'll make it that much easier for Ardern to get dirty.

She'd do well to think of cutting a deal with New Zealand First, in the fairly marginal Northland electorate for example, where Peters lost the seat to National at the last election. The Labour candidate there, Willow-Jean Prime, polled third, several thousand votes behind Peters.

Ardern could have a John Key cuppa in the electorate with Peters, as he did with John Banks standing for Act in Epsom.

Paul Goldsmith has been happy to be the invisible candidate there, secure in the knowledge he's home on the list. It's hardly damaged his career prospects either given he's now National's finance spokesman and he, like the party knows, it's the party vote that counts.

And doing electorate deals are in reality far from dirty, they're crediting the voter with some intelligence. It allows them to vote for the party they'd like to see in power at the expense of allowing a third party constituent MP to come through as a support partner and making the five percent threshold redundant.

As a greenhorn leader, Ardern now has to start thinking about her options - and making some tough decisions.

Still, chances of her pulling it off would be better than odds-on, providing she ensures what the odds are and that's why electorate deals for Labour in this environment are essential.