In February 1988, a group of lesbians abseiled into the House of Lords to protest against section 28; a few months later, Booan Temple disrupted the Six O’Clock News for the same cause. Margaret Thatcher had claimed the promotion of homosexuality was undermining the family, and as Sue Lawley read the news, you could hear Temple’s muffled shouts as Nicholas Witchell held her down. Gay men, gay women and their allies were all on the same side back then, in solidarity against Tory repression.

How we identified sexually was not paramount. We all read a lot of queer theory, but, more importantly, we knew that bodies existed in history, in a context, for we were seeing a generation wiped out by Aids. If you lived through that, solidarity took precedence over sexuality.

Now, I feel a huge sadness when I look at the fragmentation of the landscape, where endless fighting, cancellations and no-platformings have obscured our understanding of who the real enemies are.

Last Saturday, Selina Todd, a professor of modern history at the University of Oxford, was due to give a polite two-minute speech of thanks at an event at Exeter College commemorating 50 years since Ruskin College’s inaugural National Women’s Liberation Conference. The day before Todd was due to speak, she says she was disinvited on the grounds that she had addressed a meeting of the group Woman’s Place UK, which was formed in 2017 after proposed changes to the Gender Recognition Act. The group campaigns for women to have separate spaces and distinct services on the basis of our biological sex. Todd, an esteemed professor of working-class history, has, as a result, been accused on social media of being transphobic. Woman’s Place UK was recently defined as a “trans-exclusionist hate group” in a pledge put together by the Labour Campaign for Trans Rights, which the Labour leadership candidates Lisa Nandy and Rebecca Long-Bailey signed up to.

Facebook Twitter Pinterest The University of Oxford professor Selina Todd. Photograph: David Levene/The Guardian

Woman’s Place UK clearly isn’t a hate group, and the Labour pledge led to many women using the hashtag #ExpelMe on Twitter because they were uncomfortable with people being able to self-declare as a man or a woman – whatever their biological sex – for all sorts of reasons.

The radical insight of feminism is that gender is a social construct – that girls and women are not fated to be feminine, that boys and men don’t have to be masculine. But we have gone through the looking-glass and are being told that sex is a construct. It is said that sex is merely assigned at birth, rather than being a material fact – actually, though, sex is recognisable in the womb (which is what enables foetal sex selection). Sex is not a feeling. Female is a biological classification that applies to all living species. If you produce large immobile gametes, you are female. Even if you are a frog. This is not complicated, nor is there a spectrum, although there are small numbers of intersex people who should absolutely be supported.

Female oppression is innately connected to our ability to reproduce. Women have made progress by talking about biology, menstruation, childbirth and menopause. We won’t now have our bodies or voices written out of the script. The materiality of having a female body may mean rape or it may mean childbirth – but we still seek liberation from gender. In some transgender ideology, we are told the opposite: gender is material and therefore can be possessed by whoever claims it, and it is sex as a category that is a social construction. Thus, sex-based rights, protected in law, can be done away with.

I know from personal experience the consequences of being deemed transphobic by an invisible committee on social media. It has meant death and rape threats for me and my children, and police involvement. I also know that the most vicious stuff takes place online and not in real life. Still, I can’t stand by. As Roman Polanski was being rewarded for his latest film at the César awards, Todd was being silenced.

This latest silencing of women is a warning. You either protect women’s rights as sex-based or you don’t protect them at all.

If the idea of women organising autonomously is transphobic you are walking into a cul-de-sac, which absolutely traps people in boxes that benefit the patriarchy. Because there is nothing the patriarchy fears more than women who no longer rely on male authority. We revert to a society where women have to be chaperoned, not trusted to make decisions about their own reality. Meanwhile, men-only spaces are how half the establishment operates and no one considers that to be transphobic. None of this discussion is about men giving up space for trans men; it is always about what women must accept.

Most people want the tiny percentage of the population who are trans to have the best lives they can. Living your best life would be one free of male violence. It is not feminists who murder trans people, although this might be the impression you would be left with if you relied solely on Twitter for your information.

Male violence is an issue for women, which is why we want single-sex spaces. Vulnerable women in refuges and prisons must be allowed to live in safe environments – the common enemy here is the patriarchy, remember? How did we arrive at a situation where there are shocking and rising numbers of teenage girls presenting at specialist clinics with gender dysphoria, while some who have transitioned are now regretful and infertile?

Women have the right to call out the violent men who rape. We have the right to speak and organise without being told that speech is itself dangerous. You can tell me to “die in a ditch, terf” all you like, as many have for years, but I self-identify as a woman who won’t go down quietly.

There are more of us than you think.

• Suzanne Moore is a Guardian columnist