Today's Herald-DigiPoll survey will jolt the election campaign back into life after it was seriously looking like it was all over bar the shouting.
To lose a couple of percentage points could have been put down to margin of error. For National to shed close to five points within a week suggests other factors at work.
Several questions scream for an answer. Is this poll the circuit-breaker which Labour has been so desperately seeking? Is it the first indication that the overall game might have changed? Has Labour's in-your-face mix of policy shocks and attacks on John Key's record and credibility actually worked? And is Winston Peters now on a roll - and at the right time?
Or - to add a very necessary cautionary note - is this poll nothing more than a one-off blip on the screen of party ratings which have otherwise been monotonously uniform and unshifting for the past three years?
Whatever, the Herald poll is the best news Labour has had in a while. The party continues to bleed support - though only marginally in dropping to just under 29 per cent. Phil Goff's personal rating is very much on the rise.
Those dismissing National's slide from 54.2 to 49.5 per cent as an aberration will be ignoring the poll's confirmation of what other recent voter surveys have picked up - that support for NZ First is slowly climbing.
National is still within its target of 48 per cent of the overall party vote, which would still be sufficient to govern alone because of the wasted votes cast for minor parties which do not reach the 5 per cent threshold. The centre-left parties are still around 10 points behind the centre-right ones.
However, with just two weeks until election day, two things will be worrying National's strategists.
Labour's onslaught against Key may not be helping Labour, but it may be hurting National by shaking out some of its only loosely-attached support. National expected that to happen during the election campaign. That is why it set a reasonably achievable target of 48 per cent. However, a fair chunk of support has departed fairly quickly. There is always a lag between political actions and reaction in the polls. National may have more support to shed.
Worse, there is now another repository resurrecting itself to scoop up that support.
If Peters is seen to be within touching distance of the threshold, there may be sufficient momentum to push NZ First over the line as people realise they no longer risk casting a wasted vote. National does not want to find itself confronted with a rampant Peters in the campaign's final days.
The saving grace is that Peters has ruled out working with Labour. But it is his potential to strip votes off National which will concern Key and his advisers.
The margin between winning and losing this election is not that vast in National's case. If the poll does nothing else it underlines the need for Key to endorse John Banks in Epsom as the man National supporters should back.
Someone's bean counting: Worrying pointers for Labour in the bean poll run by Muffin Break. National is creaming Labour in provincial cities such as Hamilton, New Plymouth, Tauranga and Whangarei. The picture is more mixed in metropolitan areas with the Greens performing strongly.
They said it: "People at the top have got a lot of money and they take their holidays in Hawaii." - Phil Goff continues his personal attacks on the Prime Minister without mentioning John Key by name.
What's happening today: Winston Peters speaks to Ellerslie Rotary Club plus Maori Wardens Association conference in Dargaville.