That Key and English were preferred by 55 per cent to 37 per cent came as no great surprise to Labour. The party's own polling has similarly recorded Labour trailing well behind National when it comes to competence of economic management.
What really annoyed Labour was the inclusion in the poll's question of Norman, the Greens' co-leader, instead of David Parker, Labour's finance spokesman.
Labour will make Parker's appointment as Minister of Finance an effective bottom-line in any post-election talks with the Greens.
Norman makes little secret of his wish to hold the plum job. For all his efforts to talk the lingo of the economic mainstream and demystify Green economics for the average punter, he will not get it.
Labour will not relinquish control of that most powerful of portfolios for three reasons: first, to maintain outright control of the coalition and maintain its stability by having the prime minister and finance minister coming from the same party; second, to avoid panicking the many voters who are yet to be convinced that Greens are not "whacko", as Key puts it; and, third, the Greens are anyway unlikely to hold a high enough ratio of seats to Labour's to force the issue.
However, there is another reason which may well come into play and frustrate Norman's and other Green MPs' ambitions - one which no doubt will get some airing at the Greens' annual conference in Christchurch this weekend, though it will be difficult to know because the party which claims to be passionate about the concept of open government has shut the media out of just about every session.
It has long been assumed that should the next election deliver the requisite number of seats, Labour and the Greens would bury their differences and form a centre-left government.
That would still seem the most likely eventuality. But it is by no means guaranteed.
Shearer is increasingly making references to a "Labour-led" Government - not a "Labour-Greens" one.
This is in part to counter Key's demonising of such a combo as the "devil beast" by making it clear that Labour will very much be in charge.
But it is also becoming clear that Labour increasingly thinks it might be preferable to strike a deal with Winston Peters.
There is a growing belief that it might be easier to govern with New Zealand First than the Greens who can be fractious, averse to compromise, and prone to being holier than thou, and, perhaps worst of all, are in fierce competition with Labour for the same segments of the vote.
There are also strong indications that Peters is becoming less inclined to be party to a Labour-led government which includes the Greens.
If Peters were to hold the balance of power, he accordingly might well eschew a three-way arrangement with Labour and the Greens and align with National.
It would thus be in Labour's self-interest to ignore the Greens and negotiate with Peters.
The immediate difficulty with that scenario is Labour and NZ First combined would be unlikely to secure a majority in Parliament.
However, the Greens might find they had little choice but to prop up a Labour-NZ First Administration if only through abstention. The Greens would have nowhere to go.
Having briefly played touchy-feelie politics with National before the 2011 election, the Greens have since made it pretty plain that they and the current ruling party are fundamentally incompatible. The Greens would have to play ball with Labour and NZ First or risk insult and odium being heaped upon them if they were to force a fresh election.
The problem with all this hypothesising is that - apart from the risk that things could get really messy - Labour cannot be guaranteed that NZ First MPs will be returned to Parliament in 2014 in sufficient number, if at all.
The Greens will definitely be back - and in number. And, at the end of the day, Labour may be left with no choice but to work with them.
The two parties have an odd relationship. Labour and the Greens are the Siamese twins of New Zealand politics. They are forever trying to escape from one another but are doomed to having to live together. It is consequently a relationship which has the life and energy sucked out of it by an underlying and debilitating mixture of ambivalence and wariness towards one another.
The respective leaderships meet fairly regularly, but there seems to be little enthusiasm or drive when it comes to projecting a Government-in-waiting.
The closest thing to that happening was the joint press conference in April which saw Shearer, Parker and Norman share a platform to unveil their broadly similar plans to intervene in the wholesale electricity market to force down power prices.
The joint release of policy happened by accident not design, however.
Labour is not keen on a repeat. That reluctance is based on the assumption by Labour that the Greens got more positives out of the exercise than Labour did.
As the larger partner in the relationship, Labour accepts - but also resents - the fact that it must play the responsible role, while the Greens can peck away at Labour's base support by making promises they know they will not have to keep.
Meanwhile, the communication vacuum has been filled by Key and Steven Joyce with their denunciations of the Greens as anti-economic development and Labour likewise guilty by association.
There are two schools of thought within the two Opposition parties regarding National's attacks. The first says it is better to ignore the vitriol and venom on the basis that that line of attack will have been exhausted by the time next year's election campaign rolls around.
The second argues that it is a mistake to allow Key free rein to "frame" Labour and the Greens in an image which becomes harder and harder for those two parties to wipe off.
This weekend the Greens will try to render as null and void Key's potent line that next year's election will be fought between "the centre-right and far left" by claiming he is the extremist, not them. It is a claim that is most unlikely to wash, however.
Debate on this article is now closed.
