Emily Bridges, the trans woman cyclist, will not compete at the National Omnium Championships on Sunday after a ruling by cycling's governing body, the UCI.
A statement released by British Cycling on Wednesday evening said that "under their [the UCI's] current guidelines Emily is not eligible to participate in this event".
Bridges was due to take part in the Championships this weekend, but the UCI has officially said that the reason her participation is not allowed as she is still registered with them as a male cyclist, and therefore cannot compete as a woman until her male UCI ID expires.
The British Cycling statement said the body acknowledged the UCI's decision, but that they "fully recognise her disappointment with today’s decision".
It read: "At British Cycling, we believe that transgender and non-binary people should be able to find a home, feel welcome and included, and be celebrated in our sport....
"We have been in close discussions with the UCI regarding Emily’s participation this weekend and have also engaged closely with Emily and her family regarding her transition and involvement in elite competitions.
"We acknowledge the decision of the UCI with regards to Emily’s participation, however we fully recognise her disappointment with today’s decision."
Last month, Bridges spoke to Cycling Weekly about her transition and the trials and tribulations of fitting in with British Cycling's policies in order to compete as a woman. Its transgender policy stipulates that a rider’s testosterone level must be below 5nmol/L for at least 12 months before their first race.
The statement said: "Under the British Cycling Transgender and Non-Binary Participation policy, Emily Bridges was due to participate in the British National Omnium Championships on Saturday 2nd April. We have now been informed by the UCI that under their current guidelines Emily is not eligible to participate in this event."
On Wednesday, UCI president David Lappartient told the BBC that he was a "little bit worried" about trans women being allowed to compete in women's sports.
"I'm a little bit worried that [their participation in women's events] will affect the fairness of competition," he said. "I believe that maybe the situation we have now, of the rules of five nanomoles per litre [to measure testosterone levels], is probably not enough.
"When I speak with some professors in medicine, some specialists, they say, 'yes, your body probably has a memory already of what you are and so there is maybe some advantages'.
"But is there a memory from your body from what you were before - and do you have advantage for this? Is it a bridge of fair competition?"
Cycling Weekly understands that there have been concerns raised by some female athletes about Bridges' participation in events. However, last month she said: "There was a lot of positivity [to her transition announcement]: lots of really nice messages from friends and people I’d never met, mostly female cyclists, offering their support."
She also conceded, though, that there had been a "steady trickle" of hostile posts on the subject of her transition and participation in events. Lappartient told the BBC that some female cyclists had registered concerns with the UCI over fairness of competition and "do not accept" the current controls.
British Cycling called for a "coalition to share, learn and understand more about how we can achieve fairness in a way that maintains the dignity and respect of all athletes" following the UCI's ruling.
The statement read: "Transgender and non-binary inclusion is bigger than one race and one athlete – it is a challenge for all elite sports. We believe all participants within our sport deserve more clarity and understanding around participation in elite competitions and we will continue to work with the UCI on both Emily’s case and the wider situation with regards to this issue.
"We also understand that in elite sports the concept of fairness is essential. For this reason, British Cycling is today calling for a coalition to share, learn and understand more about how we can achieve fairness in a way that maintains the dignity and respect of all athletes.
"Within recent years, we’ve seen huge advancements in the science and testing around elite sports, the broader scientific and understanding of human biology, developments in protection provided by the law, and crucially a greater respect for the psychological and societal challenges of those who are transgender and non-binary. This is a complex area and by uniting, we can share resources and insights.
"We know that some of these conversations are happening in pockets of the sporting world, but we want to encourage all sporting governing bodies, athletes, the transgender and non-binary athlete community, the Government and beyond to come together and find a better answer.
"Across sports, far more needs to be done, collectively, before any long-term conclusions can be drawn."
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