This week has provided a rather frank insight into the negotiation styles of National and Justice Minister Andrew Little.
To sum it up, Little accused National of "dicking around" and "dumb politicking" while National accused Little of being "belligerent".
There have even been reports of something resembling tantrums.
The negotiations in question were over Little's legislation putting in place measures to monitor people with associations to terrorist groups upon a return to New Zealand.
It was deemed urgent because of the risk Islamic State (Isis) fighters held in Syria would return to their homelands as Turkey launched its offensive on the Syria border, where many prisoners are held.
New Zealander Mark Taylor is the case in point.
In short, Labour needs either National or the Green Party to get the bill over the line. And it needs to get that done quickly.
The Green Party wants it watered down. National wants it beefed up.
Little is stuck in the middle.
The stand-off shows just how tenuous bipartisanship can be.
It is often said that there is bipartisanship on matters of national importance such as trade, defence and national security.
But governments take that for granted at their peril.
In some respects, Little's roosters are now coming home to roost.
There were several occasions during National's time in power when Labour bucked against the convention of bipartisanship.
There was the Trans Pacific Partnership, which Labour opposed until it got into power and pretended it had been re-negotiated enough to allow it to support it.
There was the deployment of Defence Force troops to Iraq to train Iraqi security forces to fight Isis.
Labour's opposition to that prompted John Key's infamous "get some guts" attack on Labour in Parliament.
Then there was National's legislation – the Countering Terrorist Fighters Act.
That was a temporary law to allow surveillance and measures to prevent people leaving New Zealand to become a fighter for a terrorist group overseas.
When that passed in 2014, Little was the Labour leader.
Labour supported that, but only after securing changes it wanted.
Little – who now hopes to rush his own foreign fighters legislation through Parliament with a short submissions period - criticised the speed with which National was passing its legislation.
The latest round of negotiations have apparently been less fruitful.
Little and National's justice spokesman Mark Mitchell had one meeting, at which Little claimed he agreed to look at four of the seven changes National wanted.
After that, National said publicly that it would support the bill at first reading but that it wanted changes.
Leader Simon Bridges then said he would pull that support if National did not get another meeting ahead of the first reading to discuss those changes.
National's changes included extending control orders allowing monitoring of returning terrorists beyond the proposed six years, detaining them upon return, and lowering the age limit to those who would be covered from 18 to 14 years old.
Bridges set out his case, arguing that while someone who had been radicalised might well end up as a plumber happily settled with a family in suburban New Zealand, there was no guarantee of it – and no ability to monitor them after the six years was up.
Little insists he had agreed to at least four areas of change.
Those are understood to have included extending the period for which control orders would last – albeit not indefinitely.
He also agreed to make it mandatory that the orders required someone to live at a certain address and to report to the police regularly. In each case, it only partially met National's wishes.
It was apparently not enough for National.
Little can't put the bill forward without knowing it will pass its first reading.
National sees no point supporting the bill if it is clear Little won't budge on the areas they want changes.
Little can be stubborn and has a background as an unflinching union negotiator.
But Little himself has said there is no time to lose, given former Isis fighters could be returning within months.
And his only other option is to turn to the Greens.
That will lead to the bill being watered down.
There is a risk Little will put that option up as a way to try and call National's bluff.
There is an equal risk National will not fold and simply say the blood will be on Labour's hands if those measures prove to be too weak.
It seems an astonishing gap in New Zealand's legislation that while laws were passed to try to stop people leaving to become foreign fighters, no measures were taken to cater for those who were returning.
At the moment, the blame is on all sides.