Transgender cyclist Emily Bridges says she has been "harassed and demonised" after British Cycling declared her ineligible to race at this weekend's British National Omnium Championships.
The 21-year-old, from Cwmbran in south Wales, had initially been allowed to compete in the women's event under British Cyling's transgender and non-binary participation policy.
However, the governing body has since been informed by the Union Cycliste Internationale that Bridges is not eligible to participate.
In a statement posted on Twitter by her mother, Bridges explains how she has been "relentlessly harassed and demonised by those who have a specific agenda to push."
The Welsh cyclist goes on to explain how "no one should have to choose between being who they are, and participating in the sport that they love."
"My testosterone level has been far below the limit."
Bridges wrote: "For the last six months, I have been in contact with British Cycling and the UCI over the eligibility criteria I would need to meet as a transgender woman in order to race in the female category.
"In that time, I have provided both British Cycling and UCI with medical evidence that I meet the eligibility criteria for transgender female cyclists, including that my testosterone level has been far below the limit prescribed by the Regulations for the last 12 months."
Bridges goes on to explain how she was informed two days before competing that she was not eligible.
"Despite the public announcement, I still have little clarity around their finding of my ineligibility under their regulations."
Bridges - winner of the men's points race at the British Universities' championships in Glasgow in February - began hormone therapy last year.
British Cycling's regulations, updated in January this year, require riders to have had testosterone levels below five nanomoles per litre for a 12-month period prior to competition.
In her statement, she goes on to write: "I am an athlete, and I just want to race competitively again."
"I’ve had to deactivate my social media to prevent the targeted abuse I am receiving, and block websites to stop seeing them. This is despite the fact I have not yet raced in the female category.
"I have been judged despite a total lack of evidence against me, purely because I am trans."
She concluded: "I am in contact with British Cycling and UCI requesting clarity around my alleged ineligibility, and I hope that they will reconsider their decision in line with the Regulations.
"Thank you to everyone who has supported me through this, your messages have meant the world this past 10 days."