Ministers should clarify the Equality Act to make the difference between biological sex and gender clearer, the head of Britain’s equality watchdog has told MPs, in order to bring “rationalisations, simplifications and clarity” to the legislation. Kishwer Falkner, chair of the Equality and Human Rights Commission, said the commission’s board had looked at between 150 and 200 pages of advice and spent more than 11 hours discussing the subject, before sending a 19-page letter setting out its position to the equalities minister, Kemi Badenoch. Badenoch had asked the watchdog for guidance earlier this year on whether the 2010 act needed to be amended, amid confusion over whether references to sex in the law meant biological or legal sex. Suggested changes would remove outdated terminology, Lady Falkner said, adding: “Thirteen years on, society has evolved considerably in terms of its understanding of the protected characteristic of sex and gender reassignment and language has evolved.” The government is considering how to proceed. At the start of her appearance before the women and equalities select committee, Falkner made a brief statement explaining she would be unable to answer questions about an internal investigation into her leadership of the EHRC, to avoid any risk of “breaching the fairness of the process”. The EHRC appointed a senior lawyer in May to carry out an independent investigation into allegations that are understood to have been made by 12 current or former staff members against Falkner. Asked about the high level of staff departures, Marcial Boo, the chief executive, said many of those who left were pursuing opportunities for promotions elsewhere. It would be the government’s responsibility to come up with a clear definition of biological sex, before any formal clarification of the UK’s equalities legislation, Falkner said. “We didn’t define biological sex – we think it’s for government, with all legislation, to define what its terms are,” she told MPs. “So we leave it to the government, but I think most people would recognise that biological sex is a categorisation which accords with reproductive functions. “So a woman is a person whose body is designed to produce eggs and a man is a person whose body is designed to produce sperm. We’re not scientists, this is not the definitive word on it, it’s for the government to decide on how they wish to define it.” Changing to a biological definition of sex would mean single-sex groups could restrict membership to biological women or men, the EHRC said in its letter of advice, allowing lesbian support groups, for instance, to refuse admission to trans women, or to prevent the anomaly whereby trans women can benefit from women-only shortlists whereas trans men cannot. The law has a lack of clarity, Falkner said, citing, for example, discussions of the gender pay gap, which are really focused on sex rather than gender.