An Oxford University sociologist has claimed that the data on the size of the transgender population in England and Wales is "seriously flawed."
Michael Biggs has raised questions about the 2021 national census which reported that there were 262,000 trans people in the UK.
Critics had raised questions about the specific census question about trans people, which was remarkably similar to one proposed by a transgender campaign group in 2007.
The 2007 question was rejected by a separate research group because of feedback that "non-trans people would not understand" it, especially if English were not their first language.
There have been concerns raised about the stats from the 2021 Census
PA
Biggs, who is a board member of gender-critical group Sex Matters, called the research "seriously flawed."
He said: "[The census] results are implausible with regard to geography, language, education, ethnicity, and religion. The results contradict data on referrals to gender clinics and signatures on a pro-transgender petition.
"The results are also internally inconsistent when the various categories of gender identity are correlated across localities, and when compared with sexual orientation. The spurious results were produced by a flawed question, which originated with a transgender campaigning organization.
"The question evidently confused a substantial number of respondents who erroneously declared their gender identity to differ from their natal sex. Confusion is manifested in the overrepresentation of people lacking English proficiency in the most suspect gender categories."
262,000 people who indicated they were transgender on the 2021 census
PA
The suggested wording from Press for Change back in 2007 was: "Is your gender identity the same as the gender you were assigned at birth?"
The actual question which appeared on the 2021 census question was: “Is the gender you identify with the same as your sex registered at birth?”
Of the 262,000 people who indicated they were transgender on the 2021 census, 118,000 did not provide further detail. About 48,000 people, or 0.1 per cent of the population aged 16 and over, identified as a trans man, and 48,000 as a trans woman.
About 30,000 identified as non-binary, and a further 18,000 people wrote in a different gender identity. The most trans people were recorded as living in the boroughs of Newham and Brent.
A letter from the Office for National Statistics (ONS) containing information about Census 2021
PA
In October, women and equalities minister Kemi Badenoch had ordered an investigation into whether the number of transgender people in England and Wales had been "overestimated" due to people not understanding the gender identity question.
The ONS said of the question: "It is especially challenging to design a question when it involves a concept that may not be familiar to all.
"We go through a rigorous and thoughtful process to develop all questions, drawing on our expertise in question design, to help achieve the best results possible, setting out our findings transparently.
"The gender identity question went through a testing process which involved trans and non-trans people and, through the 2019 census rehearsal, people who did not have English as their main language before the final wording was confirmed through legislation.
"We have made clear where there is uncertainty in the estimates. Our users have told us that they expect higher uncertainty around census estimates for this topic, particularly as it is a voluntary question, and are not solely relying on the census estimates in isolation."