Populism does not need a real problem. It needs an enemy and a slogan.

There is a bill before Parliament that promises to settle, in two short clauses, a question that biology, philosophy and lived human experience have never settled. The Legislation (Definitions of Woman and Man) Amendment Bill, a member’s bill from New Zealand First’s Jenny Marcroft, would write into the Legislation Act 2019 that a woman is “an adult human biological female” and a man is “an adult human biological male”, and apply those definitions across every statute we have. It passed its first reading on 20 May and now sits with a select committee, with submissions open until 2 July.

The pitch is that this restores “biological reality” and gives ordinary people clarity. The problem is that the clarity is an illusion, because the science the bill leans on does not deliver a single, clean test.

Sex is not one switch. It is a cluster of traits: chromosomes, hormones, internal anatomy, external anatomy. For most people these line up, and for a meaningful minority they do not. Intersex variations are real and not rare. The bill names none of this. It does not say whether “biological female” means chromosomes, or hormones, or what a midwife records at birth, because there is no answer that holds for every body. As one philosopher put it recently, you cannot resolve what a woman is by a vote in Parliament any more than you could resolve the nature of Pluto by a show of hands at a conference.

Then there is gender, which is distinct again. Gender identity is how a person understands and lives their own place in the world, and it is not reducible to a karyotype. Here in Aotearoa we do not have to import this insight. Te ao Māori carried understandings of gender broader than the colonial binary long before that binary arrived on ships. Takatāpui is not a modern fashion; it is a reclaiming. A bill that flattens all of this into two boxes is not defending tradition. It is enforcing a borrowed and recent one.

If the bill were merely confused, that would be one thing. What makes it worse is that it is unnecessary. Lawyers have pointed out that existing law already permits single-sex spaces and sex-based sport. The Attorney-General flagged that the bill could breach the Bill of Rights by discriminating on age, because defining a woman as an “adult” quietly writes girls out of laws that currently protect them, including in areas as serious as abortion. Even National’s Minister for Women, who voted for it anyway, said she was not convinced it would advance the rights of women and girls “in any way, shape or form”.

So why are we here? Look at the pattern. NZ First has lodged close to nineteen member’s bills this term, and its own chief of staff has described a tactic of submitting, withdrawing and replacing them to generate headlines. The earlier bathroom bill followed the same script before it was pulled. This is the machinery of a dog whistle. Pick a small and already marginalised group, declare that womanhood itself is “under attack”, promise to defend the “quiet majority”, and let the resentment do the campaigning for you. The threat is invented. The fear is the product.

Populism does not need a real problem. It needs an enemy and a slogan. This bill supplies the slogan and nominates the enemy, and then asks us to mistake that for governing. We should decline. Submissions close on 2 July, and saying so plainly, in your own words, is among the most useful things a New Zealander can do before then.