“My view is, we looked at this in government and we thought four per cent was about right, but I’d kind of say if you’re going to four per cent, that is tinkering actually, four to five per cent,” he said.
“Why not have the courage of your convictions, let’s throw this out there, why not two or three per cent? Actually let’s be genuinely democratic.”
And its a good question. Because parties which get two or three percent of the vote are every bit as deserving of democratic representation as those which get five or ten or forty. There is no democratic justification for excluding them, and even the Electoral Commission fell back on snobby concerns about a "need" to keep small parties out in the cold because they were "ineffective" or "extremist". On the former, I think the Maori Party, Progressives, United Future, ACT, and their respective supporters would all beg to differ; on the latter it is simply absurd fearmongering, rooted in a snobby view that some voices simply shouldn't be heard, even if there are enough votes to elect them (that this view was propounded by an unelected body simply adds insult to injury).
The ideal threshold is none at all (let the modified Sainte-Laguë method fall where it may!) or whatever it takes to win one seat - a level which would make the "coat-tailing rule" redundant and allow it to be repealed. But any reduction is an improvement. Dropping it to two percent would make a huge difference, and if the opposition really supports that, they should get together with the government, pass a law, and save us the cost of a referendum.
(If you're curious, Graeme Edgeler has been calculating the no-threshold results for every election since 2008. You can see his 2017 results and links to the rest here. A 2% threshold would not have changed the last election, but would have seen the Conservatives elected in 2011 and 2014, NZ First in 2008, Christian Heritage in 1999 and the Christian Coalition in 1996. The reason why there is so little change is of course because the one-seat "coat-tail" rule has moderated the undemocratic effects of the threshold, and helped keep our parliament proportional).