First off, some background.
Labour's Phil Twyford has long supported one very sensible change to zoning: abolish rural/urban growth boundaries and instead put in place transport corridor designations for future growth and infrastructure funding provisions based around recouping through tax some of the uplift in values that comes from being next to the designated corridor.
The Auckland Unitary Plan fixed some of the problems with the old Metropolitan Urban Limit: the Rural/Urban Boundary is farther out than it was, and there's provision for expansion through private plan, but the boundary still can bind, and how flexible the plan will wind up being for proposed extensions is anybody's guess.
Further, ACT has long supported abolishing urban growth boundaries.
That sets the stage.
Nick Smith's bill to extend the duration of the Special Housing Areas. ACT critiqued that bill for failing to abolish the urban growth boundaries or to set out funding for infrastructure.
The bill wound up needing an omnibus Part Two for Parliamentary reasons that I don't understand. For further Parliamentary reasons that I don't understand, that meant opposition parties could put up as many amendments on it as they wanted. And so the usual shenanigans ensued.
Unfortunately, among the shenanigan amendments that had zero chance of passing (like banning foreigners from buying houses, taxing everything, the usual stuff), Phil Twyford had his amendment to abolish the urban growth boundary and to fund infrastructure.
In a House sitting under urgency with piles of, from National/ACT's view, silly amendments going through, Seymour didn't find out that Twyford's amendment was in there.
I expect that Seymour would have loved to have had the chance to have voted to abolish urban growth limits.
But he didn't find out about it. Seymour notes in the house that he had one hour's notice of the amendment being in there - if that were a phone call from Twyford, that would be Seymour's fault for not having gotten his vote in. If it were an email, I expect it would be Twyford's for not having gotten proper notice to Seymour; if Seymour had just given his proxy to National on the set of amendments, it would have taken more than an easily missed email to sort.
And so Twyford's amendment failed by one vote.
The vote to abolish rural-urban boundaries failed by one vote - and a vote that would have flipped had that vote known about the amendment.
Here's the amendment that could have been, along with a confusing-to-me suggestion that it "passed with amendments proscribing parking minima, and requirement to mitigate/adapt climate change", which I presume refers to its having passed as Labour policy rather than in the House last night.
Passed with amendments proscribing parking minima, and requirement to mitigate/adapt climate change. @TransportBlog pic.twitter.com/R4Kzs4JYbo— Phil Twyford (@PhilTwyford) September 7, 2016