Sharron Davies has accused London Marathon organisers of being "anti-women" after they failed to ban trans women from competing in the women's race today. The Olympic swimming hero said the organisation was acting "against the law" following last week's Supreme Court ruling, which found that the protected characteristic of "woman" under the Equality Act refers to biological women. Women's rights campaigners have also criticised the organisers, claiming the London Marathon is operating a "two-tier" sport after trans women were barred from the elite women's race but not the main event, according to the Mail on Sunday. Transgender participants are allowed to run the 26.2-mile course across London today as female athletes, despite the Supreme Court ruling and new guidance issued by the Equality and Human Rights Commission (EHRC) on Friday. Race times of trans women will be recorded and categorised alongside those of biological women. Ms Davies, a long-standing champion of fairness in sport who competed at three Olympics and won silver in Moscow in a race where her Soviet opponents were accused of using steroids, said: "I'm very disappointed that yet again, against the law, the London Marathon has prioritised males over females in the women's category. "At every ability and level, women and girls deserve fair and safe sport. I hope the London Marathon are held to account for their anti-women stance." On Saturday night, London Marathon chief executive Hugh Brasher reiterated the current rule that transgender women can run as females. He said: "The mass participation event at the London Marathon is not a race where participants compete against each other. It is a personal challenge." The equalities watchdog issued interim guidance following the Supreme Court ruling, stating that the term "woman" is defined by biological sex. The EHRC said trans women “should not be permitted to use the women’s facilities” in workplaces or public-facing services like shops and hospitals. However, the watchdog also stressed that trans people “should not be put in a position where there are no facilities for them to use”. The Supreme Court's ruling, delivered over the Easter period, declared that the words "woman" and "sex" in the Equality Act refer to biological women and biological sex. The judgment has been interpreted to mean that trans women, who are biologically male but identify as women, can be lawfully excluded from women-only spaces such as toilets and changing rooms. The EHRC said it issued the new guidance because “many people have questions about the judgment and what it means for them”.