Britain’s Supreme Court ruled that the word “woman” refers to biological sex under the country’s anti-discrimination law, in a blow to trans rights activists.

The United Kingdom's top court will issue a ruling on Wednesday on the legal definition of a woman under equality laws, a case that could have far-reaching implications for the fractious debate over transgender rights.

The United Kingdom's top court on Wednesday upheld an appeal by a campaign group on whether transgender women are legally women under equality legislation, ruling that the law referred to a "biological woman and biological sex".