LONDON: Thousands of people on Saturday rallied in central London in support of trans rights, after a landmark court ruling on the definition of a `woman`.

Britain`sSupremeCourtonWednesday ruled that the legal definition of a `woman` is based on a person`s sex at birth, with potentially far-reaching consequences for how single-sex spaces and services are run.

At a protest in Parliament Square, activists, protesters, trade unions and community groups waved flags and held up banners with slogans such as `trans women are women!` and `trans rights are human rights`.

`My main fear the extremists will feel empowered by this decision. Hate crimes against (the) trans community (will) go up,` said Eevee Zayas, a 32-year-old researcher from Spain, describing themself as non binary transgender.

The court ruling said that single-sex spaces and services including changing rooms, toilets and women-only hospital wards `will function properly only if sex is interpreted as biological sex`.

`Everything in the transition is going to be harder. Coming here in big numbers is very important to stand against the Supreme Court decision,` added Joe Brown, a trans woman in the process of transitioning.

Brown said other fears included not being able to access health care and children being scared to come out as trans.

The court ruling followed a legal battle between the Scottish government and campaign group For Women Scotland (FWS) involving clashing interpretations of the Equality Act.-AFP