The 4th Labour Government didn't seem to have any resignations due to scandal. Lange sacked Richard Prebble for calling him mad, but that wasn't a scandal per se. His "state house" eviction party from his ministerial home probably had a scandal or two that night.
The closest the 4th Labour Government came to a scandal sacking was Koro Wetere over the Maori Loans Affair, prosecuted by Winston Peters. But Wetere survived also. This was more an issue of competence, not scandal, so a 4/10.
The 4th National Government also had a few sackings due to scandal, but not many. Two Ministers did resign portfolios - Denis Marshall for Conservation (over Cave Creek) and Murray McCuly for Tourism (over the Tourism Board) but they remained as Ministers. Neil Kirton was sacked as Associate Health Minister over s conflict of interest, but in reality it was more about his inability to work with Health Minister Bill English - a 3/10 scandal. Cave Creek was a 10/10 (people died) but this was not the fault of the Minister, however he had to take responsibility. The Tourism Board was probably 5/10 - there was meddling, but mainly because the Minister had lost confidence in them.
Famously of course Jenny Shipley sacked Winston Peters as Deputy Prime Minister. But that was over political behaviour, not a scandal.
The one scandal-related sacking was Tuariki Delamere just two days before the 1999 general election, over conflicts of interest as Associate Immigration Minister. The election saved this being fully investigated, but on the facts that were known this was an 8/10 - Delamere was highly conflicted in his dealings.
The 5th Labour Government is where sackings started to become a regular thing. PM Helen Clark herself was investigated by the Police for forgery, after she signed a painting she didn't paint. She survived the scandal, but if charges had been laid, she may not have. A hard one to score. Probably 4/10. The PM should have known better, but there was no self gain involved.
Dover Samuels was investigated for an alleged former relationship with an under-age girl in his care. He was sacked by Clark but was cleared by the Police. I only put this as a 2/10 as the allegations were not connected to his role as an MP. He later urinated in a hotel corridor, but escaped censure for that.
Phillida Bunkle and Marian Hobbs were both stood down over allegations they were claiming an out of Wellington accommodation despite being Wellington List MPs. They were cleared of criminal behaviour but only Hobbs was reinstated. A 3/10 scandal.
David Parker lost his attorney-general portfolio after allegations of filing false returns with the companies office, but was cleared. A 1/10.
Trevor Mallard was convicted of fighting after punching Tau Henare in 2007, but was only demoted in rank, not sacked from Cabinet. Hitting someone physically is a reasonably serious thing, so I give it 6/10.
The Darren Hughes scandal saw him leave Parliament. The allegations of sexual assault were serious, so also a 7/10. Somewhat tragically Hughes could have survived the scandal if he had been stood down immediately when the Labour leadership were informed.
Lianne Dalziel was sacked by Helen Clark after proof emerged that she had lied to reporters. She was later reinstated to Cabinet. Lying to reporters is serious, but not as serious as lying to the House so 6/10.
Ruth Dyson was sacked in 2000 as a Minister after she was charged with drink driving at almost twice the legal limit. A 5/10.
John Tamihere faced allegations of financial improprieties around the Waipareira Trust which he used to run. He stood down, and the Serious Fraud Office laid no charges. However he then made very derogotary remarks about many of his colleagues to Investigate Magazine, and was never reinstated. A 4/10 scandal.
The most serious scandal in my lifetime (and probably in our parliamentary history) was that of Taito Philip Field, who eventually was found guilty of 11 charges of bribery and corruption as an MP, and 15 charges of perverting the course of justice. This was a 10/10.
Also very serious was the scandal around Winston Peters in 2008. The Privileges Committee found that he did know about the $100,000 donation from Owen Glenn to his lawyer, to cover Peters' legal costs. Peters as Foreign Affairs Minister had been advocating to have Glenn made Honorary Consul to Monaco, without disclosing the relationship and donation. I put this at 8/10. He was stood down but not sacked, and failed to be re-elected in the 2008 election. However as all know, he did make it back in 2011.
In terms of the scandals under the 5th National Government, the first and arguably most serious was Richard Worth. Not so much the allegations around romantically pursuing Labour activist Neelam Choudary, but the sexual assault complaint laid by a Korean woman with the Police. It was further alleged that he had used his Ministerial Office to arrange to fly the complainant to Wellington, so it was linked to his official duties. I give this an 8/10.
Phil Heatley resigned as a Minister over including some family expenses in his expense claim. These were pretty minor value, and he was cleared of deliberate wrong-doing. A 2/10.
Pansy Wong resigned as a Minister and MP after revelations her husband had been conducting some business activities on a couple of her taxpayer subsidised or funded trips. A 6/10 scandal.
Finally we have the Nick Smith scandal. It has led to his resignation, due to his advocacy on behalf of a friend over an ACC matter, while ACC Minister. There was no self gain involved, so I give it a 4/10 - the same as Koro Wetere got for the Maori Loans scandal and Helen Clark over paintergate.
For those interested in stats that's a total of 23 scandals, and on my scoring the average scandal scored a 5.5. Nine of the 23 scandals got a 7/10 or higher. Of course your scoring may differ - you can use the comments system to do your own score.
Note I have not included the "scandals" over MPs expenses once they started to be published, as there were so many of them. I may have accidentally missed some other scandals also as I am going off memory. In fact just remembered Ross Meurant was sacked as a Parliamentary Under-Secretary in the 1990s, due to his dealings with a Russian bank.
There seems to be no definitive listing anywhere of all the New Zealand ministerial resignations. There is one for Australia, and I was amused to read two Ministers resigned in 1982 over the improper importation of a colour television set. Back then they were hard to obtain items!
*David Farrar is a centre-right blogger and affiliated with the National Party. A disclosure statement on his political views can be found here.