Blog Symposium:
The Supreme Court Judgement on Biological Definition of Women
SYMPOSIUM Editor
Dr Jashim Chowdhury
Lecturer, Law School
Peer REVIEWER
Dr Caroline Gibby
Reader, Law School
Peer REVIEWER
Michael Makey
Lecturer, Law School
PEER REVIEWER
Dr Misbau Lateef
Lecturer, Law School
Editorial
The Supreme Court’s recent judgement on biological defintion of “women” has reignited a long lasting debate within the British society. This Symposium aims at showcasing what the Hull Law students are thinking about it. Views expressed are those of the authors. We remain open to entertain some more submissions representing viewpoints that may be different from these authors.
Elizabeth Shaw
What Defines a Woman? – The Supreme Court’s Flawed Approach to Sex and Gender
“The Court emphasises the importance of statutory interpretation, and ensuring that language in statutes is clear, cohesive, and easily applicable. However, a biological definition of sex does not provide this. Such a definition is dismissive of the lived realities of trans individuals, and appears to disregard those who are intersex, or do not fit neatly into such strict categories, seemingly ignoring contemporary scientific understandings of sex and gender as a spectrum, rather than a binary.”
Introduction
On 16th April 2025, the Supreme Court delivered a landmark judgement in For Women Scotland Ltd v The Scottish Minister. The judgement concerned the definition of “woman” under the Equality Act 2010, and whether trans people should be included under the protected characteristic of “sex”. The Supreme Court ruled that “woman” and “sex” under the Act refers exclusively to biological women, therefore excluding trans individuals, including those who hold a Gender Recognition Certificate (GRC) (a legal document that recognises a person’s acquired gender), from this legal category.
Whilst the Court claimed that their decision had no grounding in politics, the ruling undoubtedly will have a significant impact on the current political climate of the UK. The ruling aims to provide clarity in the language of the statute, however appears to disregard contemporary understandings of gender, and raises significant concerns about the potential marginalisation of trans individuals and the reinforcement of outdated notions of gender. This blog will critically examine some of the Supreme Court’s major justifications for its decisions, whilst discussing some of the legal, social, and practical implications that the judgement will have in light of the trans movement.
Background
In 2018, the Scottish Parliament introduced the Gender Representation on Public Boards (Scotland) Act 2018, which aimed to improve gender representation in the public sector by requiring that 50% of non-executive members on public boards be women. Section 2 of this act defined “woman” to include individuals with the protected characteristic of gender reassignment.
The statute’s interpretation of “woman” received criticism from the gender-critical feminist campaign group ‘For Women Scotland’, who opposed to inclusion of trans women in the definition. The group initiated judicial proceedings to challenge the statute, and, following a series of appeals, the court determined that it was beyond the legislative competence of the Scottish Parliament to redefine “woman” or “sex” (a protected characteristic under the Equality Act 2010). The court concluded that such terms must be consistent with the definitions under the Equality Act 2010, which includes trans individuals holding a Gender Recognition Certificate.
For Women Scotland challenged this ruling, arguing that “women” under the Equality Act should not include trans women. On 16th April 2025, the Supreme Court ruled in their favour, holding that “woman” under the Equality Act refers exclusively to “biological women,” thereby excluding trans women, even those holding a GRC, from the legal definition.
This decision highlights a significant legal conflict between the Equality Act 2010, which seeks to protect individuals from discrimination, and the Gender Recognition Act 2004, which allows transgender individuals to be legally recognised as their acquired gender. The case raises broader questions about statutory interpretation, gender equality, and the interaction between the two statutes.
Susan Smith and Marion Calder, directors of the ‘For Women Scotland group, outside the Supreme Court on 16 April 2025. Photograph: Tayfun Salcı/ZUMA Press Wire/REX/Shutterstock
Issues and Implications
In their judgement the Supreme Court stated that their primary focus was on maintaining clarity in legal definition. However, the assumption of the court that a biological definition of sex and gender provides a more coherent framework than a certificated definition (one that recognises Gender Recognition Certificates) is flawed.
Although sex is often interpreted as a binary of strictly male or female, contemporary understandings of sex and gender reveal a spectrum of biological variations such as intersex conditions (e.g. Androgen Insensitivity Syndrome) and hormonal differences, which defy binary classifications. The Supreme Court states in paragraph 171 of their judgement that the “concept of sex is binary, a person is either a woman or a man.” – this is inaccurate. Applying outdated binaries in law and policy fails to account for individuals who may not fit in either category, and oversimplifies the complexities of sex and gender, which could lead to the law being applied incorrectly or inconsistently. A certificated definition of sex, which would recognise trans individuals as their acquired gender, would provide a more practical and inclusive approach, protecting all individuals without discrimination.
In addition to this, the exclusion of GRCs from the definition of “woman” conflicts with the Gender Recognition Act 2004, which recognises those holding a GRC as their acquired gender “for all purposes”. The idea that trans individuals can be recognised as their acquired gender for all purposes, whilst simultaneously not be recognised as such under the Equality Act 2010, is inherently contradictory. It is flawed for the Supreme Court to justify their judgement by reasons of legal clarity and coherence, when such a ruling contradicts another major piece of legislation.
Campaigners take part in a rally organised by trans rights groups, trade unions, and community organisations at Parliament Square in central London (PA). Source: The Indepedent (19 April 2025)
The purely biological interpretation of sex presents us with a narrow interpretation of sex-based protections. Because trans women are now not considered women under the Equality Act, this means that they may be unable to seek protection under the Act for sex-based discrimination they experience, for example in workplaces or educational institutions. Whilst the Supreme Court defends their stance by reaffirming that trans individuals still have protection as they fall under the protected characteristic of “gender reassignment”, they appear to not fully address situations where discrimination is based on the perception of their gender, rather than their transition status. It is important to recognise that allowing trans women sex-based protections does not undermine the rights of cisgender women – it is important to balance and uplift the rights of both groups, rather than excluding a whole category of individuals in an attempt to defend women’s rights.
Another implication of the judgement is that it could make it easier for service providers to exclude trans women from single-sex spaces, such as shelters or domestic violence refuges. The Supreme Court argued in their judgement that if the Equality Act were to take a certificated approach to sex, this would result in inconsistent application of the law and a number of practical difficulties. The court brought up potential difficulties of distinguishing between trans women with and without a GRC, and expressed concerns about the protection of cisgender women in single-sex spaces, if service providers were not able to exclude biological men. Single-sex spaces such as shelters and refuges already have the ability to assess individuals on a case-by-case basis, and, regardless of gender identity, have the ability to exclude those who may cause distress to fellow service users. Concerns about the protection of cisgender women can be alleviated by conducting assessments on service users to ensure they are not at a risk to anyone – rather than excluding trans women simply on the basis of their gender reassignment. There is also very little empirical evidence to suggest that allowing trans women to use single-sex spaces such as public bathrooms increase the levels of sexual violence against women and children in public spaces – suggesting that fears of increased safety and privacy violations are not empirically grounded. Trans individuals are often subjected to abuse on the basis of their gender identity – with trans people being more likely to experience threats of physical or sexual harassment or violence compared with other members of the LGBT community. Trans women who are victims of domestic abuse also experience large numbers of additional needs, particularly in relation to mental health, making it all the more important to ensure that trans people have access to appropriate support services that reflect their gender identity.
The Supreme Court’s judgement will have a permanent effect on future case law as Supreme Court rulings are binding. This means that lower courts that hear similar cases concerning the definition of “woman” or “sex” are required to follow the ruling, risking reinforcing exclusionary applications of sex-based protections, and accepting discrimination against trans individuals. Whilst the Supreme Court argue that the judgement applies strictly to the interpretation of the Equality Act, the decision of such a powerful court could have the ability to influence interpretations of other pieces of legislation that refers to the terms “women” or “sex”, or laws and policies regarding single-sex spaces, for example.
The Supreme Court stated in their judgement that it is not their role to adjudicate on the arguments in the public domain. This, however, dismisses the broader social and political implications of the ruling. Concepts of sex and gender are highly debated topics in today’s society, and a judgement which excludes trans women from the Court’s definition of “woman” risks reinforcing divisions and fuelling anti-trans rhetoric. Gender-critical feminist campaign groups celebrated the judgement with champagne, whilst trans rights activists expressed fear and concern, “devastated” by the judgement. The Court’s ruling clearly favours and reinforces the attitudes of anti-trans groups, making the Court’s dismissal of political agendas difficult to swallow.
Conclusion
Overall, the justifications given by the Supreme Court for their biological interpretation of sex under the Equality Act are flawed. The Court emphasises the importance of statutory interpretation, and ensuring that language in statutes is clear, cohesive, and easily applicable. However, a biological definition of sex does not provide this. Such a definition is dismissive of the lived realities of trans individuals, and appears to disregard those who are intersex, or do not fit neatly into such strict categories, seemingly ignoring contemporary scientific understandings of sex and gender as a spectrum, rather than a binary. This interpretation of the Equality Act – an Act designed to ensure equality and to protect marginalised individuals from discrimination – ultimately disregards trans identities and has far-reaching negative consequences.
Elizabeth (Liz) Shaw is a third year Law Student at Hull who has a keen interest in International Humanitarian Law as well as issues concerning human rights and equality. She has been awarded both the John L Lambert Prize in Criminal Law and the Hudgell’s Real Prize in World Law Modules, demonstrating her commitment to academics. Alongside her studies, Liz is a multi-instrumentalist who performs in a number of Hull bands.
Rebecca Lamb-Busby & Marcus Eames
Supreme Court’s “For Women Scotland” Verdict: Merely One Battle in a Protracted War for Trans Rights?
“Just because the SC has ruled in favour of one side does not mean it is forever concrete – it can be altered. This case is merely one battle in a long and protracted war for trans rights, and it is down to those elected to create a brighter future for the trans community.”
Introduction
What does it mean to be a woman? This is a question that has been asked many times over the decades. Does it mean you like pink Barbies? Does it mean you like flowery dresses? Does it mean you have female genitalia? Recently the UK Supreme Court (SC) answered this question unanimously in no uncertain terms that “[t]he meaning of the terms “sex”, “man” and “woman” in the EA 2010 is biological and not certificated sex.” (see para 265(xviii) of the case). This was after a lengthy legal battle between the Scottish Parliament and a group of self-described feminists called For Women Scotland, claiming to “protect and strengthen women and children’s rights” in Scotland. In this article, we hope to explore how this descision came about, why it was made, the impacts it will have on the wider LGBTQ+ community and what can be done moving forward.
This legal battle came after the Scottish Parliament passed the Gender Representation on Public Boards (Scotland) Act 2018. In this they created a three-stage test defining what a woman is, and this was challenged in the Scottish Inner House (Senior Scottish Appeal Court). Here it was deemed unlawful as it created a new definition for a woman, which is a reserved matter for the UK government.
After this the Scottish Parliament used guidance from the Equality and Human Rights Commission (EHRC), a non-departmental public body in the UK, and published statutory guidance on their interpretation of the legislation. It asserted that the definitions given under the Equality Act 2010 (EA) and the Gender Recognition Act 2004 (GRA), particularly the one that defines someone’s acquired gender to be their legal sex (GRA 2004 s.9(1)), should be used. However, this was then subjected to another legal challenge as, For Women Scotland submit, the definition of a woman in the EA could not have been intended to include those defined in the GRA.
This argument was rejected by Scotland’s senior court (Inner House) and, therefore, brought in front of the UK SC where, on 16th April 2025, For Women won their appeal. In the 88-page judgement, the SC made clear the impact of such a decision. They highlighted that this does not only redefine what a ‘woman’ is but also a ‘man’, and that they have “no doubt that Parliament intended the words ‘man’ and ‘women’ to refer to biological sex” (Lord Hodge para 51 and 162).
Thousands of people marched through London following the Supreme Court’s ruling on 19 April 20225.Credit: AP
How was this decision made?
It is of considerable note that the court did not hear from any trans charities and refused to take evidence from the UK’s first transgender judge, Victoria McCloud, who believes the ruling is a “push for overt restrictions on the rights of trans people”. For her, this is the start of “real issues” in their fight for legal recognition.
During the appeal, the only charity heard in support of trans rights was Amnesty International. This is compared to the four charities that were against trans rights. This highlights how many organisations were involved in this appeal, and how it seemed stacked in favour of one side. Whilst the EHRC was also heard, they are not a charity and were instead reiterating their interpretation before the court.
Why do people agree?
Many people have expressed delight in the SC ruling, from For Women, journalists, feminists to the public. The ruling has been described as simple ‘common sense’, with people shocked that the definition of ‘woman’ needed to be decided by judges. Many have expressed feeling “vindicated and relieved”.
For Women’s co-director, Susan Smith, stated how the ruling gave clarity on the law, finally meaning that single-sex spaces, simply mean biological women spaces. Whilst she recognises that gender reassignments are protected characteristics, she argues that being a woman should not be seen as an identity that anyone could have, as it downplays the varied issues men and women have.
Lara Brown, senior researcher at think-tank Policy Exchange, supported the ruling as it allows space for segregation. One example used is where female victims of male violence want to come together in a safe space (without males) for informal therapy. Lara mentions how single-sex toilets can now be more comfortable by excluding men; the same applies for hospital wards and changing rooms. Others state the ruling allows businesses to interpret legislation easier. It should be considered, however, that questions remain over enforceability, as there are privacy and other legitimate human rights concerns.
Sport can also be very problematic, especially as many believe that transgender women, have a significant advantage over biological women due to having gone through male puberty, as some believe this gives them a larger muscle mass and more strength. This is despite some studies seeming to suggest the opposite. Swimmer, Lia Thomas, became the centre of this controversy after she jumped from being 554th in the men’s 200m freestyle to 5th in the women’s in the Ivy League Swimming Championships. Something which many point to when trying to ban trans people from sports. However, there are groups that have noted that those figures may not be fully reliable.
Broader implications for the LGBTQ+ Community
The concept of ‘passing’ is for a trans person to live their life as their gender, and be perceived by others in the same light. For these individuals, they do not seek to be treated differently by people because of their transition, although admittedly this can sometimes be out of fear. Rather, they seek to be treated as equals. The decision by the SC undermines this reality for many. Equally, this may create unenforceable standards as many ‘passing’ trans people either actively hide the attributes most associated with their previous gender, or they have had surgery which in some cases makes them indistinguishable from cis people. It is people like this that the law fails to account for. This decision only creates more division by splitting up trans people into those that are ‘passing’ and those that are not, highlighting how the system undermines trans people.
In the wider LGBTQ+ community, some lesbians accept trans women as women that they can be attracted to. However, this is viewed as a personal preference and is not representative of everyone. Still, some lesbians express interest in dating a trans woman, despite being an attraction to just women. Even then, some trans women are only attracted to women, and because of their gender identity, they themselves identify as lesbian. So, when the SC cites concerns that trans women would not make sense to be in that space, it only serves to dehumanise them due to a lack of understanding of the community and its values. Especially since it has allowed organisations like the LGB Alliance a group that, on several occasions, have been described as transphobic (particularly omitting the T in LGBT) and the Lesbian Project who are similarly controversial. In addition, it opens the door to trans women being discriminated against due to their sexual orientation, as if a trans woman cannot be a woman, she cannot be a lesbian.
Scenes from 19 April 2025 (Saturday)’s demo in Parliament Square. Photo Credit: PA, Source: ITV News 19 April 2025
Potential Impacts
The 2021 Census for England and Wales, with 45.7 million respondents, asked people if their gender that they identify with is the same as their sex registered at birth. 262,000 people (aged mostly over 16) said “No”. Equally, 48,000 identified as trans women and the same number also identified as trans men. According to the 2022 Census for Scotland, a total of 19,990 people over 16 identified as trans or had a trans history, equalling 115,990 trans people, not including data for younger teenagers. These numbers make it clear that many people across the UK will be directly affected by this ruling, not to mention the people who have yet to come out as transgender too. Showing how this judgement can have lasting effects and cause more than just legal issues.
Impacts of Mental Health on Trans People
Trans people face higher prevalence of mental health challenges, such as anxiety, depression and substance use disorders compared to cis women, likely due to factors including discrimination, violence and societal barriers of transitioning. A 2020 study found that almost 500 per 100,000 trans women face gender dysphoria, with lower numbers in trans men.
Following the Bell v Tavistock (2020) ruling which restricted gender-affirming care for those under 16, there may have been an increase in suicides amongst trans youth. Whilst this ruling is no longer in effect, the 2024 Cass Review, which banned puberty blockers, is causing more concerns for trans youth. A 2023 study found that the prevalence of suicidal thoughts in trans people globally was 50% in their lifetime; for trans women, this was 47%. Worryingly, around 50% of trans people who experience suicidal thoughts commit suicide. These concerns only grow greater the more trans rights are restricted, like in the SC’s ruling.
Where do we go from here?
Despite this ruling, there is still hope for the trans community. Unlike other countries like the USA where primary legislation can be struck down by the Supreme Court of the United States (SCOTUS), the UK SC only has powers of interpretation. The crux of the case revolved around the need to interpret the definition of a ‘woman’ in relation to the EA. The SC made it clear that due to the context surrounding the word, such as pregnancy, it could only apply to biological women. It also looked at other legislation, noting that the GRA s9(3) includes the provision that other legislation may disapply or change s 9(1), sex relating to a gender recognition certificate. Therefore, it decided that the only logical conclusion, is that Parliament had done this through the context of the legislation even if not expressly (para 99-104). It also refused to divide the term into subcategories for fear of inconsistency (para 209), deciding it is not their job to do this.
Through these actions, despite the egregious decision from the court, made due to a fundamental lack of understanding of trans issues and disregard for fairness, the court is still leaving it open to Parliament to take the lead. Popular petitions at the time of writing on the government website involve trans issues. If a petition gets to 10,000 signatures, the government must respond. If it reaches 100,000 signatures, it must be debated in Parliament. Just because the SC has ruled in favour of one side does not mean it is forever concrete – it can be altered. This case is merely one battle in a long and protracted war for trans rights, and it is down to those elected to create a brighter future for the trans community, proving we are the progressive nation we so desperately profess to be.
Conclusion
In an ever-changing society, the law needs to adapt to protect modern-day values. This decision brings us closer to ‘Trump’s America’, and further away from the Labour government’s commitment to “remove indignities for trans people who deserve recognition and acceptance.” This commitment in their 2024 manifesto is as important as ever, now that the key to change lies with this government. This small line in an otherwise lengthy manifesto can hopefully give trans people everywhere some hope of change in the wake of this devastating blow to trans rights.
For Women Scotland, under the guise of feminism, have prioritised biological women’s rights over trans women’s rights, destroying the core principle of equality they stand for. Despite this, there is still a path to change as the decades long push for trans rights will not be halted. This is just one of many setbacks in their fight to prove that no matter what, trans rights are human rights.
Rebecca is a 4th year Law with Criminology student who recently came back from Germany doing a year abroad. Passionate about International Human Rights Law, she focusing a lot of her energy on the area including participation in a couple of international summer schools. She plans to work for NGO’s promoting Human Rights and making the world a better place.
Marcus is a 2nd year law student who is about to embark on a year abroad in Germany. He has a keen interest in reforming the criminal justice system and helping those that fall between the cracks in the law. Once he becomes a criminal barrister he hopes to effect change from within, by using his experience to advocate for modernisation and the creation of inclusive legislation