Double-crossing, treachery, name-calling, suspicion, pettiness, lies and leaking have all fed some bitter feuds between politicians in Parliament.
Politicians are usually able to separate the politics from the personal enough to remain civil. But sometimes things turn ugly – even to the point of legal action.
The NZ Herald looks at the anatomy of some of the bitterest feuds in Parliament – and top of the list is Winston Peters and Paula Bennett.
Winston Peters and Paula Bennett: From fat jokes to court
Back in August 2016, Winston Peters challenged Paula Bennett to a running race through Maungaturoto, a small town in Northland.
He even offered her a 500m head start.
The challenge was part of an exchange between the two in Parliament that started when
Peters took a jab at Paula Bennett's weight. Bennett had made a reference to being "at the coalface".
Peters responded "since when was the coalface the local deli?".
Bennett responded with a dig about Peters' age, saying it was "probably the rest home that you should be in".
Since then he has also had a go over Bennett's Maori heritage, saying her "discovery of whakapapa Māori is rather like Columbus' discovery of America - purely by accident".
But name-calling is just a symptom of a much deeper grudge match, and that all relates to the election of 2017.
'Seriously bad taste': Winston Peters re-gifts Paula Bennett's bouquet
Winston Peters vs National: Paula Bennett not giving up her scalp
On September 22, the day before the election, Winston Peters signed papers in preparation for legal action against a raft of media, civil servants and politicians.
It related to news during the election campaign that he had had to repay about $20,000 after getting overpayments of his superannuation over several years. Peters had released the news in a statement, after learning two media outlets knew of it.
Those he planned action against included the media outlets (Newsroom and Newshub), government department heads, National Party staff – and Paula Bennett, leader Bill English, Steven Joyce, and Anne Tolley,
Bennett and Tolley had been advised of the overpayments by officials under the 'no surprises' policy, but have consistently denied leaking as have the others being sued.
Those papers sat and waited until well after the election and after Peters and his team had coalition negotiations with the National Party's team – which included Bennett, English and Joyce.
None had any idea what was coming.
They were eventually served papers on November 7 – two weeks after Peters announced his pick was Labour. Peters has since narrowed the legal action to Bennett and Tolley, as well as the Attorney General, State Services Commissioner Peter Hughes, and the former chief executive of the Ministry of Social Development, Brendan Boyle.
It was Peters' strong suspicion that Bennett – or someone authorised by her – had leaked the news of his superannuation overpayments that proved the breaking point for him.
But Peters was not the only one angry.
When those papers were served and it became clear Peters had been planning legal action all along, it left National feeling they had been played.
Many felt it was clear NZ First had never intended to give National a go.
Bennett took Peters' decision to side with Labour particularly keenly.
Peters has a longer history with National, which spans his ejection from the party, to the breakdown of the coalition government in the late 1990s, to former Prime Minister John Key ruling him out as a potential government partner in 2008 and 2011.
In 2017, Peters held Bill English partly responsible for NZ First's election result, which was lower than he had hoped. He pointed to English's call to "cut out the middle man" as arrogant and an attempt to get him out of Parliament.
Peters has since conceded the rise and rise of Labour's Jacinda Ardern may also have had something to do with it.
But those National players have now left and it is Bennett who is left.
Peters was also critical of Bennett in the morass of the Jami-Lee Ross debacle. After Ross claimed National's leadership had accused him of sexual harassment, Bennett revealed the behaviour in question was extra-marital affairs rather than harassment.
Peters said Bennett's revelation was "underhanded, vicious, uncalled for."
"When you see those sorts of tactics, it means you're bereft of any defence, and now you're playing for sheer hurt."
Peters also tore strips off the decision to make Bennett National's 'campaign chair' as "amateur hour."
Bennett described Peters as "gasping for relevancy."
The full depth of this antipathy was not known until news leaked to Newstalk ZB that Peters' legal team had allegedly discussed dropping his legal action against National Party's Anne Tolley and Bennett in return for the head of Bennett.
This casts some light on a slightly cryptic statement the week before in Peters' response to news Bennett had been appointed National's campaign chair.
Peters said Bennett moving on to the list was "so that the National Party can axe her prior to coalition negotiations in 2020."
One possible interpretation of that was that Peters would only deal with National if Bennett was gone.
Then came the flowers Bennett sent to Peters after his knee surgery, which Peters rejected with great churlishness.
There is one way this could be resolved: hold that running race challenge.
Of course, since then Bennett has undergone something of a makeover, and Peters has just had knee surgery so perhaps he might not be so keen on that challenge after all.
The Judas tale: Simon Bridges and Jami-Lee Ross
Very rarely has New Zealand politics witnessed a more visceral saga of betrayal and attempted destruction as that of National Party leader Simon Bridges and Jami-Lee Ross.
Ross was Bridges' chief backer when he contested the leadership, acting as his 'numbers man' and was rewarded with a front bench placing becoming a critical member of Bridges team.
He went from being Bridges' closest confidante to the man trying to bring about Bridges' destruction.
The relationship spiralled out of control after Ross started questioning Bridges' polling in caucus.
Many believed he was also unhappy that he did not get what he wanted after Bridges took over. While content with his front bench place and transport portfolio, it is understood he had wanted to stay on as chief whip - a job that gets a higher salary.
Things escalated after Bridges' travel expenses were leaked to Newshub ahead of their publication and National called an inquiry that ultimately cast suspicion on Ross, who has denied it.
At about the same time, Ross was confronted by Bridges and Bennett about reports of his behaviour toward staff and women, and put on leave.
Ross stepped down from the National Party at the same time the caucus was meeting to eject him.
He made a number of allegations about Bridges that Bridges denounced as false and defamatory, described Bridges as lacking integrity, released recordings of his conversations with Bridges, and referred a $100,000 donation he had helped broker to Police.
It is now being investigated by the Serious Fraud Office, and National denies any wrongdoing.
As the party's whip and 'bag man' handling donations, Ross had a lot of the party's sensitive internal information at his hands – including internal polling.
In response to Ross' claims that he had been accused of sexual harassment, Paula Bennett made it public that Ross was having extra-marital affairs – something Ross himself later admitted.
Ross was also struggling with his mental health, and admitted to hospital.
Ross' latest strike was his revelation, published in the NZ Herald this week, that former trade minister Todd McClay was involved in securing a $150,000 donation from Chinese billionaire Lang Lin's NZ–based horse export business.
The whole debacle damaged Bridges' already low personal poll ratings but Ross failed in his attempt to eject Bridges from the leadership.
As yet none of the allegations he made have stacked up.
Bridges and Ross have not spoken to each other – or even crossed paths incidentally – since Ross left the party.
Accidental conflict: Winston Peters and Andrew Little
The troubles between NZ First leader Winston Peters and Justice Minister Andrew Little are more by circumstance of portfolio than personal enmity, although the men do have some history.
Little has the misfortune to hold portfolios which are also hot button issues for NZ First. Justice gives him oversight of conscience issues and law and order reforms, while the Pike River re-entry was a big campaign promise for Peters.
As a result, NZ First has twice blindsided Andrew Little – first of all over his wish to repeal three strikes legislation and then with a last minute bid for a referendum on abortion.
Both instances led to a spat about bad faith dealings. Little has since revealed it was Peters himself who assured him of support for the three-strikes legislation, only for the NZ First caucus to take a different view.
Peters is also somewhat resentful NZ First is not being given enough credit for the re-entry to Pike River Mine – another portfolio held by Little.
Things are nevertheless more cordial than when Labour and NZ First were in Opposition and Little was Labour Party leader.
In early 2017, Little had described Peters' promise to be the first to enter the Pike River mine as "cheap".
Peters' desire to do just that once the re-entry was under way was predictably thwarted by the Pike River agency which said he did not have the training required, a decision Peters challenged.
In 2015 when Peters said he was standing in the Northland byelection, Little described him as "an old stager from way back" and said while he was a good campaigner, he was "in the twilight of his political career" and Northlanders would want an MP who could last the distance.
After it became clear Peters was on track to win that byelection, Little gave the nod to Labour voters to vote for Peters.
Also in 2017, Peters opined Labour under Little could fall to 22 per cent after a leaked Labour UMR showed it was at 26 per cent and NZ First had risen to 14 per cent.
Little responded by saying Peters "is a blowhard and this is blowhard politics".
"In the end this election isn't going to be fought on the basis of swinging dicks."
About a month later, Little resigned and handed over to Jacinda Ardern, who is now Prime Minister.
Peters has recently said on RNZ that Ardern's takeover ruined his hopes of becoming the second biggest party in New Zealand in that election – but next time round he would be ready.
National Party MPs Judith Collins and Paula Bennett: competitive rivalry.
The antagonism between these two can be overstated, but there is definitely a competitive edge and the chances of either being comfortable with the other being the leader are zero.
It appears to stem from their time in government from 2008 to 2017. By 2011, Collins had earned the ranking as National's highest ranked women until beset by series of scandals in 2014.
That included an alleged conflict of interest by visiting Oravida in China and her leaked communications with Whaleoil blogger Cam Slater in Nicky Hager's Dirty Politics.
Bennett reaped the rewards, becoming one of John Key's favourites while Collins was stood down for what Key said was misleading him over an allegation she had helped undermine Serious Fraud Office former head Adam Feeley.
Collins was eventually reinstated to Cabinet in 2015 after an investigation found no evidence she had undermined Feeley.
In the meantime, after the 2014 election, Bennett had been promoted to the fifth ranking previously held by Collins – and become the top-ranked woman in National.
After Key resigned and Bill English took over the leadership in December 2016, Bennett's stocks rose even higher.
English had voiced criticism of Collins' behaviour in Dirty Politics as well as early on in her political career. He had, however, mentored Bennett who became Deputy Prime Minister and also took Collins' beloved Police portfolio.
This tension has carried over to Opposition.
Collins and Bennett worked together well when National was dealing with the fallout of Jami-Lee Ross' expulsion.
But Collins is widely regarded as the most likely threat to Bridges.
Bennett has stepped into the role of loyal deputy to Bridges and is very protective of him (and her own role).
Speaker Trevor Mallard and National MP Nick Smith (and occasionally Paula Bennett and various other National MPs).
Mallard's most infamous foe was Tau Henare, but a man who played politics hard has found it coming back to bite on occasion now he is Speaker.
Mallard was charged with the dirty work when he was in Clark's Government, and is now redeeming his image through his efforts at making Parliament more family-friendly, including holding babies in Parliament and getting a playground built on Parliament's lawns.
But it will take more than that for National MPs to trust him.
There was tension around his penalties system of taking questions away for bad behaviour, a system that sparked a revolt and a walk-out by National MPs in December 2018.
Nick Smith is the most frequent target of the Speaker's wrath, sometimes deservedly.
Smith has been kicked out of the Debating Chamber more than other MP in this term - twice by Mallard and once by former associate Speaker Poto Williams.
While Winston Peters has also been ejected three times, Smith takes the lead because he was also 'named' – a stronger and rare sanction.
It was for comments such as accusing the Speaker of "covering for the Government" and protecting PM Jacinda Ardern.
On the last such occasion, Smith went straight outside to speak the media and accused the Speaker of being biased – it is a breach of the rules of Parliament to question the Speaker's impartiality and can be treated as a contempt of Parliament.
However, Mallard can hardly object. He was a critic of former Speaker David Carter, once tweeting that Carter was ""looked like Mafia don running his @NZNationalParty protection racket".
The Frenemies: National Party MP Judith Collins and Labour minister Phil Twyford
The Collins-Twyford showdowns have been one of the highlights of this term of Parliament, as Collins has mercilessly driven home the failings in the KiwiBuild portfolio and mocked Twyford.
Although robust, the relationship was saved from a descent into utter toxicity by the ability of both to joke about it, Collins describing Twyford as "my favourite".
Megan Woods has since taken over the KiwiBuild portfolio and her more po-faced handling of Collins has ruined the fun for everybody.
Old grudges: NZ First leader Winston Peters and National MP David Carter
Back in 2004, Peters sued David Carter for alleged defamation while Carter was chairing the select committee looking into the scampi industry. It related to an affidavit Carter had received which Carter said made serious allegations about Peters, and which he had sent to the Speaker.
Peters also sued TVNZ and Radio New Zealand for broadcasting Carter's comments, as well as former Act MP Ken Shirley for comments he made about the matter.
The court threw out the case, but Peters tried again when he was Foreign Minister in 2006, seeking $7 million from Carter in damages and costs.
That too was thrown out by the courts and an attempt to appeal that decision in 2011 was unsuccessful.
Peters had to pay Carter about $19,000 in costs - but it cost the taxpayer about $150,000 to foot the defence costs for Carter and Shirley. Peters had to pay his own costs for taking the action.
Peters said the use of taxpayer funds for Carter's legal costs was "rotten" and Carter should repay it.
When Carter became Speaker, Peters regularly challenged his handling of Parliament and Carter booted him out of the Debating Chamber numerous times.
Elements of the grievance carry on to this day.
There was speculation in 2016 that David Carter wanted the role of High Commissioner to London – and just when this speculation was circling, Peters announced that he would recall any political appointments to foreign posts if he did not believe the person was up to the job and he was in a future Government. The target was clearly Carter.
Carter would have given up hope altogether when Peters became the Foreign Minister.
It is little wonder that after Peters opted to govern with Labour in 2017, Carter was one of the very first National MPs to openly say he was pleased because he did not trust Peters.
Nor is a surprise that one of Peters' very first acts after getting into Government was to halt plans to build a new office block for MPs, a plan developed by Carter which Peters described as a "parliamentary palace."
Peters is not the only one to have take legal action against fellow MPs.
In 2012, Judith Collins took defamation proceedings against Trevor Mallard and Andrew Little for comments they made on radio which appeared to link Collins to the leak to media of a letter from National Party President Michelle Boag about a privacy breach at ACC.
The case was eventually settled, with both sides effectively agreeing to disagree. All three manage to have cordial relations now.
The Clayton's Feud: NZ First's Shane Jones and Air NZ chief executive Christopher Luxon.
Jones is all big talk when talking about the shortcomings of Christopher Luxon and Air NZ from a safe distance but things are a bit different when the two are in the same room.
Jones has criticised Luxon for what he saw as downgrading regional services, and for a safety video, as well as for his political ambitions.
On a recent flight from Auckland to Invercargill, Luxon thanked Jones for putting his spare time into reviewing Air NZ safety videos, and the pair buddied up for numerous photos.
Luxon is already – whether warranted or not – touted as a future leader of National while Jones – again whether warranted or not – is touted as a future leader of NZ First.
Both lack the personal history of bitterness that lies under the current National–NZ First relationship.
The photos prompted some to observe it may not be the last time the two men were seen in cahoots.