A sharp-eyed correspondent has pointed me at a pair of motions on the Order Paper appointing former MPs David Caygill and Roger Sowry as government and opposition representatives respectively to the Representation Commission. For those who don't know, the Representation Commission is the body established under the Electoral Act 1993 to draw electoral boundaries. While there are other members - the Surveyor-General, Government Statistician, Chief Electoral Officer, Chairperson of the Local Government Commission, and an appointed chair - they are supplemented by two members appointed on the nomination of Parliament. And since time immemorial, the two main parties have had a cosy deal to appoint explicitly political representatives to give themselves a say in boundary setting.
This is putting the foxes in charge of the henhouse. In the US, political input into boundary-setting has resulted in systematic gerrymandering, and a ridiculous situation where representatives essentially pick their constituents, rather than the other way round. As a result, fewer than 20% of seats in the House of Representatives are considered contestable; the rest are safe, meaning that their incumbents are effectively unaccountable to the people they are supposed to serve.
In New Zealand, the Representation Commission has done a better job, and there isn't overt gerrymandering. But there's an important principle here that self-interested politicians (or their proxies) should not be helping to draw the boundaries which will help determine who wins and who loses elections. We should be choosing them, not the other way around. If political parties want to have a say, then there is a submission process which is open to the public. They should be using that, rather than abusing their power in this way.