What a difference a week makes! It was former British Prime Minister Harold Wilson who coined the adage in the 1960s that a week is a long time in politics. And that has certainly been the case in New Zealand in the last week.

A week ago, Labour was facing the prospect of a tight race in the Roskill by-election and continuing leadership ructions over Andrew Little’s lack-lustre performance, while John Key was riding as high as ever in the polls, seemingly untroubled as he sailed relentlessly towards a fourth straight election victory next year. Today, all that has changed. Labour has had a resounding victory in the Roskill by-election (mainly because National voters saw it for the formality it was, and since the fate of the government was not at stake, chose to stay home and mow the lawns instead) thereby apparently relieving the pressure on beleaguered leader, Andrew Little. And John Key has, as dramatically as unexpectedly, decided to step aside as Prime Minister. National faces the uncertainties of having to find a new leader and Prime Minister, and adjusting to life post John Key. Labour’s glee, though restrained thus far, is barely disguised. As they see it, their nemesis has been removed, and it therefore should be plain sailing under spinnaker on the downwind leg in the race home to next year’s election.

But despite the hoopla, nothing much has actually changed. Labour is still the party it was last week, wracked by division and uncertainty (remember Nick Legget’s defection?) and Andrew Little is still the same leader he was then, failing to connect with the public or articulate a vison which resonates with middle New Zealand – the people who decide elections. A win in Roskill – a seat held firmly by Labour for all but three of the last 60 years – and John Key’s departure change none of that.

As for National, it is still the government it was last week, following the economic course so carefully steered by Bill English over the last eight years. The captain’s departure from the bridge changes nothing in that regard, nor does it suddenly obliterate the political capital the government has banked over the last eight years. In short, the election is still National’s to lose.

To be blunt, despite its brief relief induced excitement, Labour is no more a credible government-in-waiting than it was a week ago, when most commentators were writing it off. It is still the same old policies and people, nothing has changed. And given its own  succession of drawn out messy leadership challenges over the years it is in no position to point the finger at National’s far more truncated (if now a little crowded) process.  Its grim reality will return once the new Prime Minister is installed, and the momentarily jubilant MPs realise the mountain is still there to be climbed.  But this reality presents both a threat and an opportunity for National.

National’s opportunity is to pick-up and continue the lines from the John Key playbook, providing sensible, inclusive government that does not pander to the extremes. But any attempt by the new leadership to rebrand National post-Key as something else, perhaps to pander to its right wing, or to deviate towards embracing populism and extremism as the road to power would be a foolhardy risk that would deservedly doom it.  Despite some wistful dreaming amongst Parliament’s resident backwoodsmen, New Zealanders are showing no inclination to follow the Brexit and Trump mantras. National needs to remember that.

Speculation beyond that is essentially pointless at this stage. New Zealanders will take the new leadership in their stride – the summer barbecues will be the mulling grounds for their assessment and reaction, with the initial critical verdict to be known in the first round of opinion polls next year.

In the meantime, watching passively but passionately as ever from the sidelines will be John Key – a remarkable New Zealander and an extraordinary Prime Minister. He served New Zealand extremely well, and helped expand our country’s self-confidence and belief in itself. In that, he unleashed an enduring change in our society, the influence of which will be felt for generations. Very few, if any, Prime Ministers can boast that achievement, and no other Prime Minister has been able to leave office at a time of his own choosing, neither deceased, defeated, nor deposed.

As they count their Christmases, Both National and Labour need to reflect long and hard on that.