Family First New Zealand says it will appeal to the High Court against a Charities Board decision to de-register the organisation as a charity.
The Charities Registration Board says Family First has a purpose to promote its own particular views about marriage and the traditional family that cannot be determined to be for the public benefit in a way previously accepted as charitable.
The decision confirms a 2013 decision to remove Family First from the Charities Register because it did not advance exclusively charitable purposes.
That decision was appealed to the High Court by Family First, and in 2015 the High Court directed the board to reconsider its decision.
National Director of Family First, Bob McCoskrie, says it's going back to the same court.
"It appears that certain views of marriage and family are now deemed out-of-bounds by the state. We'll fight that political correctness and muzzling of free speech," he said.
"Family First will appeal this decision as far as we need to, not because we have to have charitable status to exist, but because of the threat it places on other charities and their freedom to speak and advocate on behalf of their supporters in a civil society," Mr McCoskrie said.
He said it is "a highly politicised and inconsistent decision" by the board and will have a chilling effect for many not-for-profit charitable groups who advocate for causes and beliefs.