Why National opposes UN migration compact

Todd McClay writes at The Spinoff:

As a matter of principle, National does not believe that migration policy should be governed through a United Nations framework. Migration is solely a matter for sovereign states. Each country must respond dynamically to the circumstances it finds itself in. The highly circumstantial nature of migration makes it a difficult policy area to apply a global framework to, outside of the basic tenants of human rights. For that reason alone we felt justified in our position to oppose this agreement, though as I will outline here, we have more specific concerns with this agreement as well.

This is a good point.  Some things such as the law of the sea need to be governed through a UN framework. Migration policy does not.

Kiwis have a good basis to consider ourselves good global citizens, as Bookman himself states. That is especially true when it comes to immigration. New Zealand has an excellent immigration system, we encourage talent to move to our country and welcome people who choose to come here to call our country home. National remains committed to that principle.
National is not, and will not be, the party that goes to an election calling for dramatic reductions of migrants or calling for discriminatory policies of banning people from housing markets based on the sound of their name.

We all know which party he is referring to there!

For example, objective 17 of the compact calls for a commitment to eliminate discrimination towards migrants. Wonderful, what could be wrong with this? The document then explains types of policies that could be used to do this including “sensitising and educating media professionals on migration-related issues and terminology” and “stopping allocation of public funding or material support to media outlets that systematically promote intolerance”, at the same time the document says that we must respect the freedom of the media.
But restricting speech because we don’t like it and refusing support for media based on what they say is a dangerous experiment in the limitations of basic rights. As a member of the National Party, I will regularly read or watch media that I don’t like, disagree with or feel is intolerant towards me and my party’s views and beliefs. My response is to write a column to the Spinoff, not call for the defunding or re-education of media. This is part of the problem, the commitments the document calls for do not match the specific policy settings and values of individual countries.

It is objective 17 which is the most problematic.