NZ First has announced that it wants a referendum on marriage equality, and so will be opposing Louisa Wall's bill.
This is probably a fair reflection of their elderly supporters' bigotry. At the same time, its deeply worrying, in that they think that matters of fundamental rights should be subject to a popular vote. Though somehow, I suspect they'd be less keen if it was their fundamental rights (e.g. to vote, to enjoy equal treatment under the law, or to live) in question.
Referenda are generally a good idea. But not where people's fundamental rights are concerned. People shouldn't be able to vote to have other people killed. And they shouldn't be able to vote to deny them full citizenship.