NZ First is self destructing again. The reason they do this is because they piss people off. The reason they piss people off is their party is not a collective interest. It is based on self interest of each member, starting from the very top. The party is not democratic like other parties. Winston Peters can never be removed as the party leader. That in itself goes a long way to explaining why the party is the way it is.
The government must do the obvious thing to distance itself as far as possible from the self destructive influence of NZ First and call an election as quickly as possible to try and form a new government so the voters can decide if they want NZ First to continue being a part of government in future.