As all things new come to dominate New Zealand's political landscape, National will be forced more quickly than it hoped to confront its own need for change. Tonight's poll offers succour for the party, but tolls the bell for Bill.

The first poll of the year confirms the over-arching narrative of New Zealand politics since the election and follows some pretty typical trends. But it raises a few curly questions too, mostly about new generations.

The Newshub Reid Research poll has Labour enjoying the spoils of victory and incumbency, with a 5.4 percent rise to 42.3 percent. National though still sits above it on 44.5 percent, up 0.1 percent on election night. The Greens are down marginally on six percent but New Zealand First has almost halved its support to 3.8 percent (down 3.4).

A quiet summer absent of controversey or economic woe and Labour's ability to tick off almost all of its 100 day plan ahead of schedule means its rise in support is entirely what you would expect. After years of waiting, the promise that so many Labour leaders and candidates for the leadership made during their wilderness years has finally been achieved. Their poll number "starts with a 4". Around a year ago a few observers – and some politicians – were wondering if that would ever happen again.

Of course you can add the glow of pregnancy to the glow of incumbency. The poll was taken in the days after Jacinda Ardern and Clarke Gayford announced they were having a baby, so love was in the air. The national conversation was all about Labour and labour. There's nothing like giving birth to a new generation to give your administration the sense that is the government to lead us into the future.

The Greens will be relieved to be steady and that is a testament to James Shaw's immense workload and stable hand holding the ship together during Cyclone Metiria. They now face the huge risk-opportunity of a leadership race, which could be a good showcase for the party's talent, but which just as easily could expose some of the factions and internal contradictions within the Greens.

Then there's the 'disaster' for New Zealand First. Look, no party likes to lose support and any party losing almost half its support has every right to feel like the world is ending. But it's not. It may be more than they wanted, but the trend is entirely predictable.

New Zealand First always loses something after an election, and would have expected to lose a decent chunk of its support after having been the decider after this election. It's mere commonsense to note that many of those who have voted New Zealand First in the hope it would choose National, not Labour, will be unimpressed and would have picked National when the pollsters rang. But that doesn't mean they might not return to Winston and his wiles come the 2020 campaign. And it has plenty of time to chip away at National's vote over the next two and a half years. So its MPs won't be panicked.

They will look too at Peters' preferred PM rating of 5.7 percent and take that 3.8 percent with a grain of salt. 

The one surprise in all this predictability is National's continual strength. That it remains more popular as a party than Labour wreathed in the Jacinda Effect should give its still grieving MPs some succour. It has maintained its discipline since the election and sitting at over 44 percent after it had been in power for three terms is quite an achievement. 

Notably, that support level gives it the luxury of time to plan its next move. National shouldn't need to run through leaders as Labour did. Or require the services of a Mike Moore, who came in to "save the furniture" in 1990. That will depend on the ambitions and ideological drivers at play within the party.

Yet today the inevitable rumblings about Bill English's leadership finally washed up on the public's shores. Bigger waves are coming and change is inevitable. This continued popularity under English even after a loss shows how many people still have faith in the man from Southland and leaves historians with interesting debates about the extent of John Key's power and its part in National's nine year run.

But every rule of politics says it's time for English to go. His preferred Prime Minister number now sits at 26 percent to Ardern's 38 percent. Down nine. It's hard to conceive of a way he could ever pass her again. And talking about conception, well, if English ever hoped to somehow hang on for a bit in case this three-way government imploded, those hopes are now surely dashed. First, the government shows little sign of internal tension. But most of all, Labour has a narrative about new starts and caring for Kiwi kids, apple pie and - literally - motherhood that makes it all-but impervious to a man who by the next election will be celebrating his 30th anniversary in parliament. A vote for him in 2020 reeks of looking backward. 

It's the same political truth Phill Goff had to face in 2011. Now Goff took one for the team and it may be that someone has to do the same for National. English might have been willing to do that and his MPs may have let him do that... until the baby news. Now, National needs its own new generation. Its own new face. A sense it too is looking forward, not back.

The question is whether someone who genuinely wants to be the next National PM would want the job of Opposition leader just yet. On one hand, the chances of winning in 2020 are slim. One-term governments are almost unheard of in New Zealand, least of all if they are led by only the second women in modern history to give birth in office. On the other hand, governments do run aground. Politics can turn upside down very quickly; just ask Ardern. And you only benefit from that if you are the one in the musical leader's chair when the music stops. 

What National doesn't lack is ambitious prospects. Simon Bridges may be the front-runner, but Nikki Kaye has a political narrative to compete with Jacinda Ardern and knows the PM well; she beat her twice in Auckland Central. 

But Amy Adams will desperately want a crack, as will Jonathan Coleman, as John Key II. Paula Bennett still harbours ambitions; it's hard to know whether she realises her time has passed. Judith Collins too will want the leadership, though her politics would drag the party away from its Key-English centrism. If she stands we could finally see the depth of the Key legacy and a fight for the soul of the party. Those on the right of the party who have bided their time under Key and English, see an opportunity. It could define their party for another decade. So what party does National want to be?

The old guard will have to find a way to ebb away. Not just English, but Steven Joyce, Nick Smith and Gerry Brownlee. The party's next steps need to be guided by the likes of Bridges and Kaye, with the help of Mark Mitchell, Paul Goldsmith, Todd Muller, Alfred Ngaro and Chris Bishop. It's notable and unhelpful that those mid-table players are mostly white, middle-aged men from the North Island and, frankly, National has a long tail. Hidden behind its kitchen cabinet has always been a number of weak performers in its caucus. They have to be cleared out by 2020, so the new leader needs some time.  

Anne Tolley and Amy Adams (if she doesn't win the leadership) will be vital to the party's fortunes.

But National's strength is also its weakness; that 44.5 percent means it can only go down from here. National has a target on its back. ACT – or whatever may replace it on the right – will believe it can surely win some votes off National this term. If David Seymour can't do that, he will have flattered to deceive and failed. 

Most of all, Winston Peters will be charging round the regions, looking to hoover up every vote possible. He knows National can't hold at 44 percent in Opposition and it will be near impossible – and counter-productive – to get into a struggle with Labour for at least two years.

Tonight's numbers confirm that Bill English has every reason to expect a graceful exit. His colleagues want to give him that. But he can be under no illusion; his time is up and they will be waiting for him to leave the party so they can change the music and open a few new bottles. Right now, New Zealand politics is all about new generations and new birth.