The controversial civil union law has become a defining ele' />

Civil Union could be restricted to gay couples if National wins this month's election.

The controversial civil union law has become a defining election issue, with National and its likely allies New Zealand First, United Future and Act all pushing for the law to be amended or put to the public in a referendum.

The four parties would also review the prostitution law. decriminalisation of prostitution, and the three minor parties are promoting a bill to protect the status of marriage by stating that it could only be between a man and a woman.

The "moral backlash" means that Auckland couple Bruce Bird and Jill Upchurch may have been wise to get in quickly before the chance of a civil union passes.

They applied for a licence on the day the Civil Union Act became law on April 26. Mr Bird, 47, and Ms Upchurch, 46, had been together for 26 years when they formally registered their union in May.

"I've been a feminist from way back and have always been pretty uncomfortable with the whole idea of marriage going from the Christian thing, the entrenched second-class status of women in marriage, women as a possession, and also the submerging of a woman's personality in marriage - you lose your name, you become 'Mrs Bruce Bird'," Ms Upchurch says.

Neither Ms Upchurch nor Mr Bird wanted to have children. Instead they plan to sail off next month around New Zealand, then to Tonga, and eventually beyond.

But they are just as committed as any married couple. About 10 years ago they formally exchanged vows to love and care for one other.

"It was one of those turning points in a relationship where we could go either way," Ms Upchurch says.

"We sat down and worked through it and settled on the terms and boundaries of what we expected from each other and what we wanted in a relationship and decided yes, we loved each other, so let's go forward and make it happen.

"And yes, it's been brilliant. I just wish it had been available when my father was still alive. He would have been pleased."

A Herald-DigiPoll survey in June suggests that almost half of the country's voters would go along with her. At that time 46 per cent were happy with the civil union law, 36 per cent were unhappy and 18 per cent undecided.

But National family affairs spokeswoman Judith Collins, one of the vast majority of National MPs who voted against, says the law should be changed to stop heterosexuals from using it.

National leader Don Brash was reported as telling a Grey Power meeting in Kapiti last month that he would not scrap the Civil Union Act.

But he voted against it in Parliament, saying that it should have been put to a referendum.

New Zealand First justice spokesman Dail Jones says referendums should still be held on both civil unions and the prostitution law.

"I'm not going to say it [prostitution] should be made illegal because you just know the thing can't be abolished," he says.

Christchurch City Council's bylaw restricting brothels to the inner city was overturned by the High Court in July, and Manukau City has found a similar bylaw impossible to enforce because suburban brothel operators deny that they are selling sex.

United Future deputy leader Judy Turner says the new law should be repealed and the new Government should investigate the Swedish model of making it illegal to buy sex.

Her party also proposes to define marriage as only between a man and a woman, and she would remove the status of civil unions while protecting the property rights of gay couples.

"If there was some way to provide a legal regime of recognition of your relationship and shared property and cemetery rights and probate rights and all those things where people share their lives in some way, I would support that," she says.

Two of the 20 heterosexual civil unions so far involve couples who were previously married. Any of those 20 can change their status to marriage by applying to the Registrar of Births, Deaths and Marriages, but at present same-sex couples cannot marry.

NUMBERS

Civil Union - first four months
Male-male: 68
Female-female: 68
Male-female: 20
Total: 156
Male-female marriages in the same period: 3955 (est)