British middle-distance runner Alexandra Bell says she is considering taking legal action against UK Athletics after being overlooked for funding for the Tokyo Olympics.
Bell produced Britain's best performance in the women's 800m semi-finals at the 2019 World Championships.
But the 27-year-old was not selected for UKA's world-class programme.
"I'm not the first athlete who's probably gone through this, but I want to be the last," she said.
Bell used social media to blame her omission on Barry Fudge, the organisation's head of endurance.
She has now threatened to take the matter further, telling BBC Sport that UKA had behaved "disgracefully" and treated athletes "like dishcloths".
"I would welcome legal advice and legal action because it's not right what they've done," added Bell.
"I'm happy to stand up for when something's not right. And that's what I intend to do."
In a statement, UKA said it did not comment on individual cases, adding that selection decisions were "discussed thoroughly" and that every athlete was "treated fairly and with respect at all times".
Fudge has declined to comment.
Ten days ago, after losing her appeal against the ruling, Bell posted on social media that despite meeting the selection criteria, she would was "never going to get a chance" of funding while Fudge was at UKA.
Having now been told by UKA that her application for a second appeal has been rejected, Bell has expanded on her allegations, claiming Fudge told her he believed she did not have "medal mentality" when she missed out on selection for the European Championships last year.
"That was one of the reasons for my appeal," Bell said. "He's always going to have this opinion of me.
"He doesn't know me from Adam. I just don't understand how I can be judged on his opinion."
Bell is also unhappy an athlete representative was not allowed at the selection meeting, and claims she was denied the minutes from the ruling.
"It's just three or four summary points, not extracts, not minutes" she said.
"One point is that the panel do acknowledge I achieved all the criteria needed...but say because I have not achieved a global medal, or made a final in the past, they predict it's a very slim chance that I'll do so in the future.
"It's ridiculous, it's just not consistent. There is a lack of transparency."
UKA makes the point that decisions on funding are made by a panel, rather than an individual, and insists there is always a neutral observer, independent from the governing body, in attendance.
A source insisted that athletes who ask for details of the meeting are given "appropriately anonymised minutes of key information relevant to the decision".
Fudge has also previously endorsed Bell's selections for this year's World Championships and European Cross Country Championships.
With rival 800m runners Lynsey Sharp and Shelayna Oskan-Clarke chosen ahead of her, Bell says she has missed out on £15,000 of funding, but is still aiming to reach Tokyo 2020.
"It's going to be a struggle. But you look at the last two years and I've managed without it," she said.
"I'll continue to strive to reach my goals and achieve my dreams.
"It's not about the money. You can't take that away from the people who are on the funding. They've done whatever they can to get on to it, and I completely appreciate that.
"But everybody's scared to say something as they don't want to jeopardise the future. But people need to say something.
"I've gone through this twice now, and I just don't want any other athletes to do the same."
Bell says she has received "overwhelming" support since speaking out.
In a statement, a UKA spokesman said: "We do not comment on individual cases in relation to the world-class programme (WCP) selections.
"The 2020 Olympic WCP selection policy, approved by UK Sport, fully outlines the process in relation to WCP selections and the appeals process available.
"During the 2020 selection process, it was identified that 68 athletes who were not previously supported by the WCP in 2019 had met or achieved a minimum performance standard outlined in the selection policy, meaning more than 140 athletes were considered for membership on to the WCP.
"The purpose of the Olympic WCP is to support athletes to win medals at the Olympic Games and therefore there are many tough decisions to be made during the process of selection. These decisions are discussed thoroughly and in depth and each and every athlete is treated fairly and with respect at all times."
Fudge is already facing questions over UKA's relationship with disgraced coach Alberto Salazar and the now-disbanded Nike Oregon Project.
He was the point of contact when Salazar was appointed as a consultant to the governing body's endurance programme in 2013. But the coach was banned in October for breaking anti-doping rules, and UKA's handling of the scandal is now the subject of an independent review.