Census
(asked on 28th April 2025) - View Source
Question to the Cabinet Office:
To ask His Majesty's Government, following the decision of the Supreme Court in For Women Scotland Ltd v The Scottish Ministers [2025] UKSC 16 on 16 April, whether they will review Census 2021 data and publish data based on male and female biological sex.
The information requested falls under the remit of the UK Statistics Authority.
Please see the letter attached from the National Statistician and Chief Executive of the UK Statistics Authority.
Professor Sir Ian Diamond | National Statistician
The Rt Hon. the Lord Blencathra
House of Lords
London
SW1A 0PW
1 May 2025
Dear Lord Blencathra,
As National Statistician and Chief Executive of the UK Statistics Authority, I am responding to your Parliamentary Question asking, following the decision of the Supreme Court in For Women Scotland Ltd v The Scottish Ministers [2025] UKSC 16 on 16 April, whether Census 2021 data will be reviewed and published based on male and female biological sex (HL6931).
Sex is a core demographic variable of fundamental importance for a range of census users providing vital information for national and local population statistics. In Census 2021 for England and Wales, as in all previous censuses, a binary sex question asked whether respondents were female or male. Supporting online guidance for this question from 9 March 2021 onwards stated, "If you are considering how to answer, use the sex recorded on your birth certificate or Gender Recognition Certificate.” This was changed on 9 March from guidance based on legal documents, following a court order[1].
The sex variable in Census 2021 data is based on the sex recorded by the person completing the sex question[2]. We cannot retrospectively change the basis on which those data were collected and defined, nor would it be possible to accurately derive a new ‘biological sex’ variable based on responses to one or more Census 2021 questions.
The Government Statistical Service (GSS) is currently prioritising work to develop new harmonised standards for data on sex and on gender identity. This will include providing guidance for official statistics producers on definitions, survey questions, suggested presentations, and information for data users. The new standards will be developed through rigorous research and testing with a range of users. It will also include learnings from the experience of other countries and their census data collections, as well as from the independent report published by the Department of Science Innovation and Technology, the Review of data, statistics and research on sex and gender[3]. This work will also take account of any relevant guidance issued by the UK Government following the Supreme Court ruling of 16 April.
Yours sincerely,
Professor Sir Ian Diamond
[1]https://www.ons.gov.uk/news/statementsandletters/updatedstatementoncensus2021sexquestionguidance