The Supreme Court has granted the attorney general leave to appeal a decision on Family First's charitable status.
In August, the Court of Appeal set aside the Charities Registration Board's 2017 decision to deregister the lobby group as a charity.
That meant Family First qualified as a charity.
In 2018, the High Court upheld the board's decision to remove the charity, because it said promoting traditional family values was not charitable work.
The board brought on the attorney-general in September as a party to appeal against the latest decision, reflecting the attorney's role as the "protector of charities".
Family First national director Bob McCoskrie told RNZ in September that the move to appeal the decision to set aside his organisation's deregistration threatened freedom of speech, belief and open debate.
McCoskrie also said the board was inconsistent in with the way it treated other charities doing similar work.