It was a weekend of in-house celebration, as New Zealand First gathered in Tauranga for their annual conference and to mark their 25th anniversary.

Leader Winston Peters told the 500 or so party members there for his keynote speech on Sunday, that the party's staying power comes down to the quality, and loyalty of their members - who have stayed the course.

He told them they had his heartfelt thanks, and that this was a day for them to celebrate.

But that is pretty much where the love-fest ended.

It was an annual conference light on major policy announcements - but heavy on attacks.

Delegates voted to back the party introducing the Respecting New Zealand Values Bill - that would see migrants and refugees having to officially sign up to a set of principles.

Things like gender equality, freedom of religion, and respect for New Zealand law.

MP Clayton Mitchell described it as a way to counter-attack intolerance, with intolerance and that if people are bigoted, racist, or xenophobic - they can go back where they came from.

This is playing into a base, that, many would argue, irrationally fear the impacts of immigration, and that our society will be overrun by 'the wrong kind of immigrant'.

But using intolerance as a weapon against intolerance to ally these fears, sounds like a sure-fire way to endorse bigoted, racist and xenophobic behaviour.

Another target that came under attack was the media. In the same breath as saying he despaired for the state of New Zealand media because of the lack of investment from our corporate owners and championing the vital role we play as the fourth estate, Winston Peters was cutting the "uncritical, mindless media swarm" for the apparent false narrative we've been spinning about disagreements amongst the coalition.

But the most scathing attack was reserved for the blue team and its captain.

In perhaps an attempt to justify to members, who would've preferred New Zealand First to go the other way in coalition talks - Peters described National as leaderless, moribund, vacuous, and a shell of its former self.

On his home turf of Tauranga, Peters labelled Simon Bridges a desperate man, and said there was no way he'd still be at the helm come the 2020 election. He said National's behaviour since the election has vindicated his wisdom in choosing the red team (with support from the green team).

But it's an interesting play from a party that prides itself on not going into elections with anyone coalition partner in mind.

This brutal attack rightly raised the question of how he could legitimately take that position in 2020.

But Peters tried to keep the door open - saying National could reform itself, and find a true leader, before then. And that the party has never done any deals behind voters backs and they're not about to change a quarter of a century-long tradition now.

And while two years is like a lifetime in politics, it seems like a lot of water would have to pass under the bridge to convincingly sell a convenient allegiance shift by then.

But as Peters told the party faithful on Sunday, they have defied history, and their past is now their prologue and who knows what the next chapter could have in store.

Peters told the party faithful on Sunday that they've defied history, and their past is now their prologue so we'll see what the next chapter, and next 25 years has in store.