A Scottish charity may be discriminating against transgender staff after announcing a change to bathroom access following the recent UK Supreme Court ruling on the Equality Act, say legal experts.

In a leaked email sent to Citizens Advice Scotland (CAS) staff last month, its chief executive claimed the charity was bound by "legal constraints" following a recent Supreme Court decision in April on how "sex" should be interpreted under the Equality Act 2010.

The ruling stated that, under the Equality Act 2010, the definition of "woman" refers to "biological sex". Following the ruling on 16 April, 'gender critical' campaigners claimed the decision had brought "clarity on the law" and described the decision as "a massive relief".

But lawyers have since pointed out the ruling on the definition of "man" and "woman" relates to the 2010 Equality Act only, and campaign groups have raised concerns over the interpretation of the ruling.

In an email on 6 May, chief executive Derek Mitchell said CAS would be enforcing a policy of "male only" and "female only" toilets on the basis of sex assigned at birth. This, he said, was in response to the ruling and subsequent interim "guidance" offered by the Equality and Human Rights Commission (EHRC), which is the UK's human rights regulator. A separate, single-occupancy WC would be available "for any colleague", he clarified.

Mitchell also wrote: "As an employer, CAS is required to comply with the law, and we need to ensure our practices and policies reflect current legal standards. This is not an expression of any view on the High Court ruling, it is our legal obligation as an employer." Two days later Mitchell sent a second update that acknowledged the upset that had been caused, but doubled down on claims that the charity was bound by the law to introduce changes.

Staff told The Ferret they were left feeling hurt, afraid and disappointed by the decision and concerned by the claim this decision had been taken out of the charity's hands by legal changes.

It's almost like it's polluted my work.

Staff member, Citizens Advice Scotland

Lawyers and campaigners told The Ferret that the EHRC update was neither intended as formal guidance nor legally binding, therefore giving employers options on how they proceed. They also warned that caution must be taken to avoid legal challenges.

When approached by The Ferret, Citizens Advice Scotland said it recognised "this issue touches on deeply personal experiences and we will continue to monitor and review our approach should guidance change".

Staff at CAS, who spoke on condition of anonymity, claimed neither the trade union or the equality, diversity and inclusion committee were consulted ahead of the announcement.

One worker claimed they no longer felt able to come out as trans at work, saying that "this is not a safe place to be". Others described how CAS had built its workplace culture around inclusion and dignity, and that this policy change was effectively a "slap in the face".

"It's almost like it's polluted my work," said one staff member. "Because obviously when we consult , we're very respectful of any kind of pronouns. So I would like to think that we would treat our colleagues the same, and that the attitude from management would be the same."

Another said the decision to put this out "without going through proper channels to make sure that the information that he's putting in there is correct" made them feel "less safe within the organisation".

Since the ruling, legal professionals and campaigning organisations including the Good Law Project, have raised concerns over how it is the interpreted and whether or not it will impact other legislation that governs access to toilets and changing rooms in the workplace.

Explainer: The Supreme Court gender ruling

Jen Ang, a human rights lawyer and director of legal firm Lawmanity, was shown the leaked emails. She said: "The Supreme Court decision does not require employers to provide only separate toilets f...