One thing should be blindingly obvious to Labour after last night's 1 News Colmar Brunton poll.
It needs to do what it can to help New Zealand First win an electorate seat at the 2020 election – and the most likely target is Northland where Shane Jones is expected to stand.
That does not mean doing a deal with New Zealand First.
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New Zealand First leader Winston Peters has eschewed the mere contemplation of such deals for so many years that it would be pointless for Labour to raise the prospect of a formal deal.
But Labour helping New Zealand First does not require New Zealand First's permission.
It requires Labour making it clear what it wants its supporters to do in its own interests.
The most likely way for Labour to return to Government is if both its partners in Government are returned, the Greens and New Zealand First.
As last night's poll reinforces, the smallest movements in support for smaller parties could have a profound effect on the election result under MMP.
New Zealand First recorded 4 per cent on last night's poll and without an electorate seat, would have been out of Parliament.
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National and Act combined would have had more MPs than Labour and the Greens and been able to form a Government.
If New Zealand First had had an electorate seat, its 4 per cent would have brought in five MPs and Labour, the Greens and New Zealand First would have had the numbers to form a second-term Government.
As last night's poll showed, New Zealand First's fortunes could be the difference between Labour getting a second term or being a one-term Government.
There is no guarantee that New Zealand First would go with Labour again, although it might not have a choice if National leader Simon Bridges rules out working with the party.
Bridges is expected to set out his party's options in February.
A Labour-Greens combination is the dream coalition for those on the left who are continually frustrated by the brakes that New Zealand First has applied to such policies as the capital gains tax and fair pay agreements.
But Labour can hardly afford to gamble. It is in its interests for New Zealand First to be returned.
Northland is held by National's Matt King with a 1389 majority. He won it in 2017 from Winston Peters, who won from National in the 2015 byelection.
It is the only obvious seat because it will have a high-profile New Zealand First candidate and it has already exercised tactical voting to New Zealand First's great advantage if you look at the past three elections, including the byelection.
In 2014, the first year that Labour's Willow-Jean Prime stood, she got 25.89 per cent of the candidate vote and she was beaten by National's Mike Sabin, who got 52.74 per cent.
New Zealand First did not even field a candidate there in 2014.
In the byelection, the one time when Labour actually did encourage tactical voting for Winston Peters, it worked remarkably well.
Andrew Little made it clear in the closing days of the contest that voting for Peters was an option. Peters got 54.45 per cent of the vote, Willow-Jean Prime got 4.67 per cent and National's Mark Osborne received 39.42 per cent.
In the 2017 election, when no signal was given to Labour voters other than to support Prime, Prime's share of the electorate vote increased to 21.61 per cent, and Peters with 34.81 per cent lost the seat to Matt King with 38.3 per cent.
Because New Zealand First hurdled the 5 per cent threshold with 7.2 per cent, it didn't need the safety net of an electorate seat to keep MPs in Parliament.
Three years in Government may change that. Peters was elected on the list.
And Willow-Jean Prime was elected anyway on Labour's list. She has already been reselected for the Northland seat for 2020.
She is a promising first-term MP with fair chance of becoming a minister in a second-term Labour Government.
Ironically, the most likely way of that happening is for a large swathe of her 8599 supporters in 2017 to vote for the New Zealand First candidate next time.