The EHRC listed hospital wards, lavatories, changing rooms and women’s refuges among spaces where they could limit access based on someone’s biological sex if it “is a proportionate means of achieving a legitimate aim”.

A senior Government source on Thursday night told The Telegraph: “The Health Secretary welcomes this guidance from the EHRC and will be asking the NHS to take it fully into account as part of the review into same-sex wards.”

Mr Javid has made a number of interventions in the heated debate in recent days, including saying that sport should be based on sex not gender and urging caution on banning conversion therapy for trans people. 

A hard-fought campaign by health professionals and patient groups saw NHS Trusts ordered to eliminate mixed-sex wards more than a decade ago except in circumstances where it was clinically necessary, such as critical care. Breaches must be reported, and hospitals face fines if they do not comply.

However, “Annex B” in the NHS’s 2019 policy on eliminating mixed-sex wards states that trans patients should be accommodated according to the gender with which they currently identify.

‘Self-identification a risk to privacy of women’

Campaigners warn the self-identification policy written by health bosses poses a risk to the privacy and dignity of women and overrides the law as set down by Parliament.

That policy is currently under review, but concerns have been raised after The Telegraph revealed that the process is being carried out by Dr Michael Brady, the national adviser for LGBT health at NHS England and a prominent trans “advocate”.

Before the review has even concluded, Dr Brady has written to campaign groups telling them that there is “no plan to reduce existing rights of trans people” and praising the contribution of controversial charities Stonewall and Mermaids.

A coalition of women’s groups have written to Mr Javid asking for him to intervene to ensure that the review process is open and transparent.

Bev Jackson, a co-founder of the LGB Alliance which was among the groups to raise concerns, said on Thursday night that they were “delighted to hear Sajid Javid’s intervention in support of single-sex wards”.

“However, in order for this to be meaningful, we must have a clear understanding of the term “biological woman”, she said, warning that the idea that self-identified gender supersedes sex in all situations is having a “worrying” influence in the training of NHS staff.

“LGB Alliance, along with a large number of concerned NHS professionals, will be happy to meet the Secretary of State at any time to discuss these issues in more detail,” Ms Jackson added. 

After the EHRC published its guidance, a spokesman for the NHS said it would be “considered as part of the ongoing review”.