In case Labour is getting any crazy ideas about protecting bigotry in their "marriage equality" bill, they might want to check out the Court of Appeal for Saskatchewan ruling In Re Marriage Commissioners Appointed Under The Marriage Act 2011 SKCA 3. That ruling upheld earlier rulings by the Saskatchewan Human Rights Commission and the Saskatchewan Court of Queen's Bench that marriage celebrants had no right of "conscientious objection" (i.e. bigoted discrimination) to same-sex marriages, and that any law allowing them to do so would violate Canada's Charter of Rights and Freedoms. A core part of the ruling was the finding that:
Marriage commissioners do not act as private citizens when they discharge their official duties. Rather, they serve as agents of the Province and act on its behalf and its behalf only. Accordingly, a system that would make marriage services available according to the personal religious beliefs of commissioners is highly problematic. It would undercut the basic principle that governmental services must be provided on an impartial and non-discriminatory basis.New Zealand is not Canada, but the same logic applies here. All celebrants here are public officials. They do not solemnise marriages as private individuals, but as people performing a public function - which means the Bill of Rights Act applies to the performance of that function. And the BORA forbids discrimination by the government on any of the grounds listed in the Human Rights Act - grounds which include sexual orientation.
A marriage celebrant cannot refuse to marry someone because they are Maori, or Catholic, or pregnant, or disabled. Why should they be allowed to refuse to marry people because they are of the same sex? If bigots don't want to perform same-sex marriages, they can simply not be celebrants.
(Of course, who the hell wants to be married by a celebrant who doesn't want to do it? But there's an important principle of secular, non-discriminatory government at stake here).
It is hard to see how an amendment to allow private bigotry by public officials would not attract an adverse BORA report (in which case why would anyone vote for it?) And it is hard to see how it would not subsequently be overturned by the Human Rights Review Tribunal. Either way, it wouldn't be worth supporting. Equal marriage yes, bigotry no.