When Ms Ellis changed her recorded gender in 2011, the law would not allow the couple to stay married if she and her wife had female birth certificates.
"In those days the sky would have fallen and the earth would have tilted off its axis and swarms of locusts would have swept the Earth, so in order to get congruent identification documents, I had to end the marriage to my wife," she said.
They could have divorced or had an annulment, but to stay together they chose a civil union: "To be perfectly honest, I was a bit grudging about it ... I'm putting the best face on it, and I'm going to enjoy getting married again. But in a lot of ways, the civil union felt more like a funeral than a celebration."
The couple are looking forward to throwing a big party with about 70 wedding guests.
Ms Ellis, a member of TransAdvocates who has been fighting for transgender prisoners' rights, said it was important to have a passport that accurately reflected who she was.
She is seeking Labour's nomination to contest the Whangarei seat this year.
"I'm a good scrapper and a good advocate ... I've ended up with people wanting me to have a crack at the Labour Party candidacy here.
"But the sad thing is that, inevitably, people seem to only be interested in the fact that I'm transgender and the fact that I've had a bit of difficulty to legally hang on to my wife."
APN News & Media