Transgender people have “a fundamental right” to be recognised in their legally acquired gender, the supreme court has heard in a case brought by Scottish campaigners to resolve how women are defined in law. For Women Scotland is challenging a prior ruling by the court of session in Edinburgh, which found that Scottish government guidance extending the definition of “woman” to transgender women with a gender recognition certificate (GRC) was lawful. Ruth Crawford KC, responding on behalf of Scottish ministers on the second day of submissions, said that the Gender Recognition Act 2004 was clear that a GRC changes sex “for all purposes”. Someone with a GRC is entitled to legal protections “just as much as others enjoy those protections who are recorded as a woman at birth”, she said. Therefore the legislation created “a fundamental right and a human right to be recognised in one’s acquired gender”. Crawford denied the document was “some legal fiction”, as described in court yesterday by For Women Scotland’s KC Aiden O’Neill. She said it had “far-reaching consequences”, not just for an individual’s recognition in state records but also their relationship to private organisations. Also speaking for Scottish ministers, Lesley Irvine highlighted the “onerous conditions” which have to be met to obtain a GRC, including a medical diagnosis of gender dysphoria and proof of living in the preferred gender for two years. She said that it amounted to a “fundamental change of status until death”. The hearing marks the conclusion of a long-running court action by For Women Scotland over the Gender Representation on Public Boards (Scotland) Act 2018, which they argue has wide-ranging ramifications for women’s rights under the UK-wide 2010 Equality Act. Crawford said that the UK parliament did have gender recognition law in mind when enacting the Equality Act and that legal recognition of change of sex “does not run contrary to the aims” of that act. Asked by Lady Simler whether there could be a “chilling effect”, whereby a lesbian association felt it had to admit transgender women, Crawford said she did not believe there was. She said that one of the intervenors in the case – Scottish Lesbians, for example – could set up exclusions on the basis of their gender critical beliefs. Crawford was asked about the possibility of a pregnant individual changing their sex to male via GRC and then being unable to claim maternity protections. She said that signing the certificate meant intending to live as a male until death but this “deep political water” was for parliament to resolve, not the court. Intervening for the Equality and Human Rights Commission, Jason Coppel KC said that, while agreeing with Scottish ministers on how gender recognition law should be currently interpreted, the case highlighted the need for parliament to consider amending the Equality Act to specify biological sex. The court will deliver its judgment at a later date.