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Feminism: Sex and gender discussions

Should the UK have a simple, clear legal definition of sex, male and female?

83 replies

SingleSexSpacesInSchools · 30/05/2026 22:09

To follow on from https://www.mumsnet.com/talk/womensrights/5533120-5533120-should-the-gender-recognition-act-be-repealed?page=6&reply=152596360 where 96% of voters said the Gender Recognition Act should be repealed

However, repealing the GRA alone could leave a legal gap. The GRA is not the only source of confusion. Some of the problem comes from older case law too.
There is already case law with the phrase "woman for all practical purposes" in it. This comes from a 2004 House of Lords case involving a transsexual police applicant. The applicant was male, had undergone surgery, and wanted to be treated as female for the purposes of police work. The issue was whether that male could be excluded from the job because police officers sometimes had to carry out same-sex searches. Before the GRA, the court decided that a post-operative transsexual person could be treated as their acquired gender for some practical purposes, including same-sex searches.

That is exactly the kind of ambiguity that needs fixing. Parliament should not simply repeal the GRA and leave older “practical purposes” arguments sitting there as the fallback position.

Whether the GRA is repealed, amended or left in place, we need legislation that clearly and unequivocally states the legal definition of sex, male and female.

The legal definition should say something like:

  • for the purposes of any Act, statutory instrument, public function, policy, data collection, sex-based rule, sex-based exception, sex-based service or sex-based protection, sex means biological sex in human beings, being male or female
  • male means a person whose body developed along the male pathway, organised around the production of small motile gametes, sperm
  • female means a person whose body developed along the female pathway, organised around the production of large immobile gametes, ova
  • man and boy mean male
  • woman and girl mean female
  • sex is observed and recorded at birth, not assigned; a birth record may be corrected where there has been a genuine recording error, but sex is not created by paperwork
  • actual fertility is not required; a person does not stop being male or female because of age, infertility, miscarriage, menopause, hysterectomy, vasectomy, injury, difference or disorder of sex development, medical treatment or surgery
  • people with DSDs are still male or female; DSDs are variations in the development of male or female bodies, not a third sex, and people with DSDs should always be treated with dignity, privacy and respect
  • sex is not determined by chromosomes alone, hormone levels, height, strength, appearance, clothing, hairstyle, voice, breast size, genital appearance, personality, social role, stereotypes, brain claims, feelings, belief or identity
  • sex is not changed by a Gender Recognition Certificate, passport, driving licence, NHS record, deed poll, self-identification, social transition, hormones, puberty blockers, cross-sex hormones, surgery, certificate, document, administrative record, or any other document or procedure
  • non-human examples, such as clownfish or plants, do not alter the legal definition of sex in human beings
  • gender reassignment remains a separate protected characteristic
  • trans people remain protected from discrimination, harassment and victimisation under the Equality Act; this is about defining sex clearly, not removing ordinary legal protections from trans people

This would not stop anyone living as they wish. It would not remove ordinary protections against discrimination, which should always remain. It would simply stop the state and public bodies from treating sex as a paperwork exercise.
Sex is real, binary and immutable. Most of the time, sex does not matter. But in the contexts where it does matter, it matters profoundly: safeguarding, privacy, dignity, data, sport, prisons, healthcare and single-sex services.

A proper legal definition would cut through years of ideological confusion and make the law clear again.

OP posts:
ExitPursuedByABare · 01/06/2026 18:04

I’ve voted no as we shouldn’t bloody need it.

World’s gone mad.

PrettyDamnCosmic · 01/06/2026 18:00

SingleSexSpacesInSchools · 01/06/2026 16:55

Look I'm not being difficult here but thats definitely NOT a definition. thats not what a definition is. It says male, or female, it does not define those words so it is not a definition.

By definition your legal biological sex is whatever is written on your original birth certificate. How it got to be recorded as M or F is pretty irrelevant but it's a data point that will be correct for 100% of individuals except for a tiny number of individuals with DSDs where the original birth certificate is replaced with a new original birth certificate. It's an infallible definition. Everybody knows what sex is recorded on their original birth certificate even those with a GRC who get issued a replacement birth certificate.

MyAmpleSheep · 01/06/2026 17:06

PrettyDamnCosmic · 01/06/2026 16:44

that's not a definition though.

Of course it is. Everybody knows what sex is on their birth certificate. It's following the definition of biological sex in Corbett v. Corbett that it's fixed at birth and determinable by three specific, innate physical criteria: chromosomes, gonads, and genitals. The latter is enough for 99.95% of babies but further investigation of chromosomes may be necessary for the very few where there is a DSD.

The latter is enough for 99.95% of babies but further investigation of chromosomes may be necessary for the very few where there is a DSD.

Chromosomes, genitalia and gonadsmay all need further investigation. Corbett doesn't say chromosomes win out.

Corbett leaves the possibility open that someone can be legally male even if they are XX, or female if they are XY in chromosomes. Because in difficult to tell cases the court can make an individual decision, based on medical advice. Until that individual difficult case is brought before a court there is of course no way to tell how a court will rule.

It's also possible that the sex recorded in the register of births (and copied to a birth certificate) is was wrongly recorded, on the Corbett test. There is a recognized procedure for making a marginal note to say so.

The overriding point is that sex has nothing to do with social factors nor an individual's choice, nor is it open to question in the great majority of cases where gonads, genitalia and chromosomes do align.

SingleSexSpacesInSchools · 01/06/2026 16:55

PrettyDamnCosmic · 01/06/2026 16:44

that's not a definition though.

Of course it is. Everybody knows what sex is on their birth certificate. It's following the definition of biological sex in Corbett v. Corbett that it's fixed at birth and determinable by three specific, innate physical criteria: chromosomes, gonads, and genitals. The latter is enough for 99.95% of babies but further investigation of chromosomes may be necessary for the very few where there is a DSD.

Look I'm not being difficult here but thats definitely NOT a definition. thats not what a definition is. It says male, or female, it does not define those words so it is not a definition.

OP posts:
MyAmpleSheep · 01/06/2026 16:54

The law isn't there to state facts; we should leave that to encyclopaedias. Neither facts that are true, nor "facts" that aren't. Day is day and night is night regardless of whether there is a law that says "day is night".

Legal definitions operate only within the law. This sounds trite, but it's important. The law cannot legislate to force people to use particular words in certain ways. What it can do is be clear how the words used in laws are to be interpreted.

Like I said earlier, if (even) everyone suddenly agrees to call a cat a dog, that doesn't make the Dangerous Dogs Act suddenly applicable to cats. Cats were not included in the mind of the legislators when the act was passed. They don't get added by dint of a later change of the meaning of a word.

Society can agree that that trans-identifying men are somehow "women", if it wants. (It doesn't want, but that's another issue). Even if that became true it doesn't affect how prior laws are to be read.

FWS didn't really clarify the meaning of men and women at all, because it has never been unclear. What it clarified is which meaning is the one that applies within the EA2010.

And no definition is ever going to stop some men from standing up to say they're women; they will simply say that your new definition is wrong.

PrettyDamnCosmic · 01/06/2026 16:44

SingleSexSpacesInSchools · 01/06/2026 16:33

that's not a definition though.

that's not a definition though.

Of course it is. Everybody knows what sex is on their birth certificate. It's following the definition of biological sex in Corbett v. Corbett that it's fixed at birth and determinable by three specific, innate physical criteria: chromosomes, gonads, and genitals. The latter is enough for 99.95% of babies but further investigation of chromosomes may be necessary for the very few where there is a DSD.

SingleSexSpacesInSchools · 01/06/2026 16:33

PrettyDamnCosmic · 01/06/2026 16:27

We already have a legal definition of sex. It's what is on your original birth certificate. No further definition is required.

that's not a definition though.

OP posts:
PrettyDamnCosmic · 01/06/2026 16:27

SingleSexSpacesInSchools · 01/06/2026 14:52

This has been a great discussion so far, lot's of points raised I had not considered. Honestly went into it thinking, well of COURSE thats going to be a yes.

Wanted to summarise the positions again a definition in law:

  • We already have a legal meaning of sex, especially after FWS
  • Opening the law up again could be risky, because badly drafted legislation could make things worse.
  • Ordinary people already know what male and female mean, so we should not concede that sex is complicated.
  • The real problem may be paperwork, records and institutions ignoring the law, rather than the lack of a definition.

And the arguments for:

  • FWS clarified the Equality Act, but only that
  • People are still standing up in court saying they are “biologically female” despite being male.
  • A clear definition would stop the endless “it’s complicated” wriggling.
  • Accurate recording of actual sex matters for healthcare, crime data, safeguarding, prisons, sport and population-level decisions.
  • Women should not have to keep litigating the same basic reality over and over again.

I'm not really swung by the arguments against except the one related to drafting a bad law or definition - or far worse possibly - a future government changing the definition to something truly mad and bad for the GC position. That does feel possible. But if things have got that bad, surely the argument would have been lost in public opinion?

Part of my reasoning to have a definition would be to make it easier to criminalise bad actors who enter single sex spaces that don't match their sex. And I think that is going to be needed because I don't think there is going to be widespread compliance with the EHRC code, not to mention the fact that the responsibility is on the service providers, not the users.

We already have a legal definition of sex. It's what is on your original birth certificate. No further definition is required.

SingleSexSpacesInSchools · 01/06/2026 14:52

This has been a great discussion so far, lot's of points raised I had not considered. Honestly went into it thinking, well of COURSE thats going to be a yes.

Wanted to summarise the positions again a definition in law:

  • We already have a legal meaning of sex, especially after FWS
  • Opening the law up again could be risky, because badly drafted legislation could make things worse.
  • Ordinary people already know what male and female mean, so we should not concede that sex is complicated.
  • The real problem may be paperwork, records and institutions ignoring the law, rather than the lack of a definition.

And the arguments for:

  • FWS clarified the Equality Act, but only that
  • People are still standing up in court saying they are “biologically female” despite being male.
  • A clear definition would stop the endless “it’s complicated” wriggling.
  • Accurate recording of actual sex matters for healthcare, crime data, safeguarding, prisons, sport and population-level decisions.
  • Women should not have to keep litigating the same basic reality over and over again.

I'm not really swung by the arguments against except the one related to drafting a bad law or definition - or far worse possibly - a future government changing the definition to something truly mad and bad for the GC position. That does feel possible. But if things have got that bad, surely the argument would have been lost in public opinion?

Part of my reasoning to have a definition would be to make it easier to criminalise bad actors who enter single sex spaces that don't match their sex. And I think that is going to be needed because I don't think there is going to be widespread compliance with the EHRC code, not to mention the fact that the responsibility is on the service providers, not the users.

OP posts:
SwirlyGates · 31/05/2026 22:46

SingleSexSpacesInSchools · 31/05/2026 19:53

dropping this here before responding to other responses!
https://www.reddit.com/r/transgenderUK/comments/1tt09hw/how_can_i_become_female/

Oh my word, the batshittery is off the scale.

DrSpartacularsMagnificentOctopus · 31/05/2026 21:28

Firstly, I'm another who thinks sex does not need to be defined additionally to existing law.

Everybody knows what sex is, what sex they are, and can identify the sex of another person with reasonable certainty.

Defining sex in law would be like defining human in law. It's unnecessary because everyone knows already.

Anyone claiming it's complicated, or ambiguous, or that sex is a spectrum or a construct, or whatever, so what? People believe all sorts of things that aren't true.

What matters isn't what people believe, what matters is the correct interpretation and application of existing law.

Secondly, I don't believe that "gender reassignment" needs to be a protected characteristic. Anyone facing discrimination and/or harassment for not conforming to the gendered expectations of their sex (whether they claim a transgendered identity or not) could easily be protected under the protected characteristic of sex.

borntobequiet · 31/05/2026 20:18

Bonkers.

SingleSexSpacesInSchools · 31/05/2026 19:53

dropping this here before responding to other responses!
https://www.reddit.com/r/transgenderUK/comments/1tt09hw/how_can_i_become_female/

OP posts:
BridgetPhillipsonIsACowardlyJobsworth · 31/05/2026 18:46

I was just rereading what I wrote last night:

I think your idea is necessary, and I would welcome it.

I think, after having read some of the points put forward by other posters about all the case law, I guess I have changed my mind about thinking it is necessary. I think we have the case law we need, it's just that, having grown up in the US, I like laws that are specific, infallible, and written down! I'm not a fan of case law and laws which, to me, look "stretchable."

I would still welcome a definition, carved in stone, untouchable, and unexploitable (that's not a word, is it?) -but, on balance, I don't think we need it at the moment. Time to move forward with action.

BridgetPhillipsonIsACowardlyJobsworth · 31/05/2026 18:35

This reply has been deleted

This has been withdrawn by MNHQ at the poster's request.

Yes, all of this. Normality. Normal functioning of law and government, normal functioning of services. No more pandering to special interest groups who want to bring their whole selves and fetishes to work. No more political statements in the hospital wards and around our medics' necks. No more inventing crimes because the police can't control the crime we already have. A country where words go back to meaning real things, not fantasies. I want normal life back. Frankly, most of us remember what normal life looks. It really wasn't that long ago!

OpheliaWitchoftheWoods · 31/05/2026 18:17

This reply has been withdrawn

This has been withdrawn by MNHQ at the poster's request.

PrettyDamnCosmic · 31/05/2026 16:57

It's what's on your original birth certificate.

This is your legal sex. There is no need for any further more complicated definition.

BridgetPhillipsonIsACowardlyJobsworth · 31/05/2026 16:55

But - if we truly already had a clear, unarguable definition, we would not keep ending up in court over whether male people can sometimes be treated as female in law.

SSSIS, I know that you know this, but we keep ending up in court because too many people are breaking the law. That's it. Creating an "unbeatable " definition of sex for the purposes of the law (leaving aside for the moment that we have the case law, as others have mentioned) would not stop the same people and organizations breaking the law (or it would not stop all of them, or enough of them).

If it were a simple thing to do, yes, I would like a clear definition. But, as others have said, it might end up being exploited, and I still think it would take too long to debate (crazy, right?) and we'd never get there.

And even if we did, we would still have people who would think it was morally right to keep breaking the law, and so we'd still end up back in court.

I want to start changing the way people act, and return to something like normality. If that means more court action for 10 years, and that's the only thing that speaks to people, then it's 10 more years of court action. Eventually we might be able to change people's attitudes, but let's start by actioning the laws we have.

TonTonMacoute · 31/05/2026 16:48

SingleSexSpacesInSchools · 31/05/2026 11:01

"Everybody Knows"

I know

you know

But that is not enough when institutions, HR departments, hospitals, schools, prisons and even tribunals are still having to argue about it.

The Sandie Peggie / Beth Upton tribunal is a good example. Dr Upton gave evidence along the lines that because Upton was biological and identified as female, Upton was therefore “biologically female”. The tribunal did not accept that. It said Upton’s sex for the purposes of the Equality Act was male, and that sex under the Act is biological, binary and immutable.

But the fact that this argument could be made at all, in a serious employment tribunal, shows the problem.

We also had the tribunal discussing things like appearance, transition, “physiological attributes of sex”, whether those attributes had changed, and whether a male person could be allowed to use a female changing room depending on the circumstances.

People know what sex is. The issue is that public bodies have been allowed to behave as if they do not, or as if paperwork, presentation, hormones, surgery, HR policy or “being kind” can somehow change it.

Thats why we need a definition, even though we all know. People aren't confused (generally), institutions keep pretending to be confused.

Of course the people who won't accept the fact of biological sex are going to continue challenging the matter, as long as they have funds to do so. It's just pester power. It's a real drag, but we just have to stand our ground and keep fighting them off.

Slimtoddy · 31/05/2026 11:29

I am no lawyer but isn't there a risk that if you try to define sex it might end up being defined as something more wishy washy that includes people who think they are the sex they are not. It could make things more unclear

SingleSexSpacesInSchools · 31/05/2026 11:25

SwirlyGates · 31/05/2026 11:22

OMG I just watched one of those stupid facebook reels, where someone interviews a right-on person and asks him, "What is a woman?" The answer of course, is "Anyone who identifies as a woman." How do they not understand that this is a circular definition? How do they get to adulthood and remain so stupid?

Because we have failed to teach critical thinking skills in schools, instead teaching kids things they don't need for the modern world of knowledge work. There is no structure of analysis of logic and reason.

Another one of my pet subjects....

OP posts:
borntobequiet · 31/05/2026 11:25

Wearenotborg · 31/05/2026 07:45

But you have males claiming to be female. Are you saying they are just batshit and deluded?

Pretty accurate

SwirlyGates · 31/05/2026 11:22

OMG I just watched one of those stupid facebook reels, where someone interviews a right-on person and asks him, "What is a woman?" The answer of course, is "Anyone who identifies as a woman." How do they not understand that this is a circular definition? How do they get to adulthood and remain so stupid?

SingleSexSpacesInSchools · 31/05/2026 11:18

5128gap · 31/05/2026 11:12

No. You are making an error in thinking that if sex were defined in detail it would be defined as per your specifications. The last thing we need is to open up the idea that sex is something insufficiency well understood it needs a new definition of any sort.
We know what it means. If people want to argue it means something different the onus is on them to prove their case.

I don’t think “leave it alone, everyone knows what sex means” is working.
People are already arguing sex means something different. Public bodies are already acting as if it does. Look at the Leonardo case. Even after FWS, a female employee lost over a policy allowing trans women, ie biological men, to use the women’s toilets.

So the clarity we have is clearly not enough in practice. I don’t want Parliament to invent a new meaning of sex. I want it to make the existing meaning impossible to wriggle around: sex means biological sex, and no certificate, identity, hormones, surgery or HR policy changes that.

Obviously I have no lever to get this passed or written

But it felt like the only solution to deal with the issues that may fall out of repealing the GRA, and going back to the “for all practical purposes” issues.

I think everyone here is making some very good points about he possible repercussions of doing the definition

I think New Zealand has a good chance of passing a definition soon as well?

OP posts:
MyAmpleSheep · 31/05/2026 11:17

SingleSexSpacesInSchools · 31/05/2026 11:10

"Yes but we already have this definition in law"

Yes things are much better post FWS Supreme Court

But - if we truly already had a clear, unarguable definition, we would not keep ending up in court over whether male people can sometimes be treated as female in law.

A definition that needs repeated litigation, Supreme Court clarification, EHRC guidance, workplace tribunals and public bodies being dragged back into line is not clear enough in practice surely?

The law has left enough gaps, contradictions and paperwork loopholes for institutions to pretend they do not know.

But - if we truly already had a clear, unarguable definition, we would not keep ending up in court over whether male people can sometimes be treated as female in law.

Apparently, we would.

Male people can sometimes be treated as female in law. It says so in the Gender Recognition Act. Nobody is genuinely uncertain as to what biological sex refers to, or how it’s determined. That is simply a diversion disingenuous people argue when they don’t like the conclusions courts (and others) correctly come to about those limited circumstances where men can be treated as women.

If anything needs to be made clearer it’s the GRA.

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