Family First NZ says it will be deregistered as a charity because of its views on gay marriage.
National director of Family First Bob McCoskrie said the group has received notification the Charities Commission intends to deregister the organisation.
He said the decision was highly politicised and showed groups that think differently to the politically correct view will be targeted.
"The Commission argues that Family First's efforts to represent the voice of 80 per cent-plus of families on the anti-smacking law or half of New Zealanders on attempts to redefine marriage, for example, have no 'public benefit', and that it is in the 'public interest' for Family First to be deregistered."
He said the timing of the notification was cynical, in that the Commission deliberately held off until after the final reading of the gay marriage bill, despite saying a final decision would be made at the end of January.
Mr McCoskrie said other reasons given for deregistration were that it had held a conference and invited speakers that promoted its viewpoint, and that it invited people to join.
"But it did say that one of the things was that we supported a view of family that was not in the public interest."
Under the Charities Act, registered charities can undertake political activities, such as supporting or opposing legislation in its area of activity, but not as its main purpose.
Charities must be set up wholly and exclusively for charitable purpose and public benefit.
Mr McCoskrie said Family First's main purpose was education and research on families.
It was a non-profit organisation funded by donations and gifts, and relied heavily on volunteer time.
He said the trust had made no change to its operations since gaining approval as a charity and undergoing two audits.
The trust had requested details on who had complained about the trust, and on whether any pro-gay marriage organisations had been the subject of similar investigations.
Loss of charitable status would not affect the work of the trust, he said.
"We will continue to represent and be a voice for a massive proportion of New Zealanders on many social and family issues."
FAMILY FIRST'S INCOME
Family First's most recent audited accounts listed on the Charities website show it has one full-time and one part-time staff member, working a total of 65 hours a week on average, and two volunteers working an average two hours a week.
Income from donations for the year ended March 2012 were just over $300,000, with a total income of $317,336.
The trust spent $30,000 on salaries and wages, and $296,505 on 'service provision'.
Major costs were $62,262 spent on 'public issues', $55,946 on 'value your vote', which collated how politicians voted on family issues, $33,870 on holding a forum, and $24,691 on research and resources.
Other expenses included postage and printing, media monitors, petrol and vehicle lease, website, and travel.