Our analysis includes laws that relate specifically to England and Wales as well as laws which also extend to Scotland and Northern Ireland, e.g., see Ministerial and Other Maternity Allowances Act 2021, s7(1). 2 Political contestation over the terms of sex and gender-in what they mean, what they include, and how they operate as material enactments-makes their usage complicated. Our use of gender does not refer principally to identity or expression but to socially institutionalised processes that draw and maintain hierarchical distinctions. These also work with and give meaning to material forms of embodiment, conventionally understood as sex. Thus, we refer to gender in contexts where some sex-based feminists would prefer to talk about sex. Where the law refers explicitly to 'sex', we follow this terminology. However, English law is often inconsistent in its usage of these terms.