New Zealanders are poised to elect the 'gayest Parliament in the world' in September

The current "rainbow caucus" say there's still plenty to do for LGBT Kiwis, even after same-sex marriage's legalisation.

There are currently seven out-and-proud MPs in New Zealand's 120-seat House of Representatives.

That will swell to nine on the basis of current polling, and up to 11 should the Greens increase their vote on election day.

Nine rainbow MPs - or 7.5 per cent - would see New Zealand pass the UK, which has 45 open members in the 650-member House of Commons, or seven per cent.