Imagine if a politician went on TV and said ‘The Earth is flat’. Or ‘Man didn’t really land on the Moon, you know’. We would worry about that politician’s fitness for public life. Well, Dawn Butler has just done the trans equivalent of that. She appeared on Good Morning Britain yesterday and said babies are born without a sex. That is easily as loopy and anti-scientific as saying the Earth isn’t a sphere.

Butler, the Labour MP for Brent, was taking part in another discussion about Labour’s interminable slide down the trans rabbit hole. Labour has completely lost the plot on this issue.

Last week, a group called the Labour Campaign for Trans Rights issued a purge-like document insisting that everyone in the Labour party bow down to the mantra that ‘trans women are women’ and ‘trans men are men’ or risk being branded a transphobic bigot and booted out of the party.

Dawn Butler: “A child is born without sex.” pic.twitter.com/e3AwyJCqQG February 17, 2020

To put this bluntly, this means if you do not accept that someone with a penis and a beard who calls himself Sharon is a woman — a complete woman, as much as your mother, wife or sister is a woman — then you are a hateful creature who has no place in the Labour party.

It’s mad, clearly. And yet leadership candidates, including Butler, rushed to sign it, despite protestations from feminists who think people with penises are blokes, not women, and who presumably also think two plus two equals four, pesky thought criminals that they are.

On GMB, against a gently questioning Richard Madeley, Butler appeared to defend the threatened purge from Labour of anyone who believes in biological reality. To say she doubled down is an understatement. She said ‘a child is born without sex’. Cue dropped jaws across the land.

Her point, presumably, is that the ancient human habit of saying ‘It’s a boy!’ or ‘It’s a girl!’ when a kid is born has always been a nasty, transphobic imposition on kids who actually should be allowed to decide for themselves what their own sex is.

To hell with biological truth. To hell with millennia of knowledge about the mammalian differences between the sexes. To hell with what we know through study and experience to be true. No, all that matters today in this era of hyper genderfludity and widespread sex denialism is the right of the individual to decree whether he is male or female.

The idea that a baby is born without sex is obviously nuts. But it is also the logical conclusion to the increasingly irrational, anti-scientific ideology of transgenderism. A key component of Labour’s new trans policy, and of trans campaigning more broadly, is that people should be allowed to identify as whatever sex they please.

I could click my fingers and say ‘My name is Brenda and I am a woman’, and hey presto, I become a woman. An actual woman. A real woman.

Feminists are completely right to describe this as a misogynistic idea. First, because it reduces womanhood to little more than a pose, a posture, an identity you can adopt with mere words, with mere declaration.

And secondly because it would allow biological males — yes, there is such a thing, Dawn — to enter women’s spaces, including their changing rooms, domestic violence shelters, and even all-women party shortlists. Even women’s prisons. Last week, Lisa Nandy said male rapists who transition to become women should be sent to women’s prisons. This is a deeply alarming and outright dangerous idea.

We need to recognise the seriousness of all this. A senior Labour figure is flat-out denying scientific truth on national TV. Another senior Labour figure is proposing putting male rapists into close, walled quarters with vulnerable women. This is backward thinking. It feels like a kind of hysteria, where otherwise sensible people are saying things that are clearly untrue and even unhinged.

Boris Johnson must be delighted. Labour is demonstrating to all just how unelectable it has become. How far down the road of deranged wokeness it has gone. All those decent, working-class ‘red wall’ voters who switched to the Tories in the December election — and who know that there are boys and girls and men and women — must be congratulating themselves right now.

Who in their right mind would vote for a party whose prospective leaders think sex isn’t real, biology is a myth, and violent men should be allowed to live with vulnerable women?