What do bodies with cervixes, chest-feeders and people with vaginas have in common? The answer is the dictionary definition that Labour MP’s dare not speak: woman.

It seems all of a sudden this week that many are awake to the oppressive inability to discuss biological definitions of the sexes. And for that, we must thank Sir Keir Starmer. Not for his inadequate defence of biology, but for revealing the peculiar post-modern cowardice that renders politicians unable to state the differences between men and women.

Andrew Marr asked Starmer on Sunday morning if “someone who thinks that only women have a cervix are welcome in the Labour Party”. The barrister’s prowess was unrecognisable in the flaccid floundering that followed.

The reluctance to discuss sexual anatomy might be why we have given definitions away so easily

Nick Ferrari then put Labour MP and Shadow Chancellor Rachel Reeves on the spot on Monday by asking if it was wrong to say that “only women have a cervix”. She spluttered, stuttered, deflected and pronounced the debate “unproductive”, then went on to say she wasn’t comfortable discussing women’s anatomies. This reluctance to discuss sexual anatomy might be partly why we have given definitions away so easily.

We all know the differences between men and women. Presumably Keir Starmer does too, since he managed to have children. So why is it so hard to say? And do definitions matter?

Starmer has not only betrayed the truth, but because he did not directly defend her views, he has also betrayed MP Rosie Duffield who has been accused of “transphobia”.

A Labour Campaign for Trans Rights launched in 2020 asserted that “trans women are women” and “trans men are men”, and that “there is no material conflict between trans rights and women’s rights”, and called for the expulsion from the Labour Party of those with transphobic views. This was signed by Lisa Nandy, Angela Rayner, Rebecca Long-Bailey, Emily Thornberry and many more.

Lisa Nandy said male rapists should be allowed to serve their sentences in female prisons if they identify as women. In defining trans women as women and believing that there can be no material conflict rights, she would house male rapists with women. It’s not hard to see how that could go wrong and how unfair it is for female prisoners. So, yes, definitions do matter. And all who disagree are presumably to be expelled from the Labour Party, according to hardline campaigners.

It is easy to agree that “Trans rights are human rights”, as Shadow Women & Equalities Secretary Anneliese Dodds said at the Labour Party Conference yesterday. Of course women’s rights and men’s rights are also human rights. All human rights matter. But sometimes there are material conflicts of rights, especially when it comes to women’s sex segregated spaces such as women’s refuges, prisons and sport.

Labour campaigners concerned about all-women shortlists being open to trans women claimed that 300 women quit the Labour Party in 2018 over the row. You can trace the history of women’s disenchantment with the Labour Party from that furore to the present day by reviewing the hashtag #labourlosingwomen on Twitter. Or, if we are to go by The Lancet’s latest front cover, perhaps that be #labourlosingbodieswithcervixes

The Labour Party have tied themselves in knots trying to advance trans rights while failing to acknowledge that sexism and sex-based rights are rooted in biological sex.

I’m sorry to admit it, but I spoilt my ballot in the last election. Aside from a general lacklustre disillusionment with the politics of the day, I was affronted by politicians’ basic inability to speak the truth. I scrawled “Women don’t have penises” in frustration across my ballot paper. In case there was any doubt, I illustrated my point with a cartoon.

Some might think quibbling over the dictionary definitions of man and woman is trivial compared to the economy, immigration, Brexit, crime — any of the big-hitter voting priorities. But it’s about truth, acknowledgement of truth, and the consequential policies within health, education, sport, crime. If you are the half of the population who must be described in eerily dehumanising terms about the functions of your body, it matters. Sex matters.

Labour needs politicians with the balls — or ovaries — to speak the truth.