I'm pretty certain there will be 49 Labour, 6 Green, 1 Progressive, 2 Act votes against = 58.
I'm also pretty sure there will be at least 1 Maori Party vote against (but possibly more) = 59.
And presuming National has a conscience vote on the issue (which I think they will) there should be a minimum of 7, but as many as 18 votes against.
There could also be 1 NZ First and the other 3 Maori Party MPs.
So my take would be a minimum of 65 vote against, or as many as 80 vote against.
This is good news, but it all hinges vitally on National having a free rather than a whipped vote. Katherine Rich and Simon Power are reportedly fighting hard for this, but it may depend on whether Don Brash is still drinking Murry McCully's kool-aid and wanting to pursue a strategy of cultural warfare against the "non-mainstream". Which means it is now vital to lobby those National MPs; the likely suspects are in the list here, and the full list is here.
Again, if we want a liberal and tolerant New Zealand, we need to speak up for it. So please pick a National MP and email them today.
Update: Updated quote with correct numbers.