For Caster Semenya, the new Olympics rules are not about providing clarity and protecting women's sport but caving into political pressure, and discriminatory.
Having fought athletics chiefs over her own gender eligibility, the double Olympic champion is shaping up for a new battle with the International Olympic Committee.
"If we have to say women must stop taking part in Olympics, so be it," the South African said in an exclusive interview with Sky News.
"I will encourage athletes to come together as a class action ... because this does not make sense. It does not save women's sport."
The South African is encouraging a challenge against the landmark decision to reintroduce sex testing alongside banning transgender women and athletes - like herself - with differences in sex development (DSD) from women's competitions.
"I'm fighting for women's dignity," Semenya said. "Those who say, 'I am not going to be tested to prove that I'm a woman' ... I will encourage them to do that to stop this nonsense."
This goes beyond sport since Donald Trump seized on stopping "men beat and batter female athletes".
IOC President Kirsty Coventry, a former Olympic champion swimmer, and many other women in sport now align with the US president.
The Zimbabwean determined it is not fair for biological males to compete in the female competitions because physiological advantages of having gone through male puberty, or the presence of XY chromosomes, can be the difference in determining medals.
"This regulation is totally shameful," Semenya said. "It's something that her as a president should have not allowed such to happen."
But the IOC has said there is at least a 10 per cent advantage in most running and swimming events for men - rising beyond 100 per cent for sports requiring "explosive power" like boxing, which creates dangers beyond fairness of competitions.
I put this to Semenya.
"Based on what?" she responded. "There's no scientific proof about what has been said. It's an ideology."
The full scientific research behind the decision has not been published. Nor has the IOC said what has changed in recent years scientifically or medically.
But is it not clear in combat sports there are safety concerns when a biological woman takes on a fighter who was born a man, with higher testosterone levels and greater muscle mass?
"What do you expect in boxing?" Semenya responded. "We understand that it's a dangerous sport. We all sign in, in all sporting codes, knowing that there are safety precautions.
"There are risks, but you cannot come and then try to measure someone's power based on how they look because you think they're intersex or you think that they're transgender."
Semenya has become the face of scrutiny of eligibility rules since her gender was questioned based on her appearance after winning gold at the World Athletics Championships as a 19-year-old in 2009.
Enforced verification tests showed that while she always identified as female and had female traits, Semenya also had the typical male XY chromosome pattern and high levels of naturally occurring testosterone.
After being cleared to race, Semenya was still able to win Olympic gold in 2012 and 2016.
But then she refused to artificially reduce her hormone levels as required by World Athletics and lost further legal challenges. So the 35-year-old now coaches.
Mandatory sex verification testing for all entrants into Olympic women's events will ensure a competitor isn't singled out for tests because they might have masculine characteristics.
The IOC's stance has transformed since ruling out a return to the "bad old days" of sex testing during Paris 2024 when Thomas Bach was in charge.
But Semenya said: "There is no respect for women. The minute you start asking a woman to be tested to take part in sports, that's not dignity."
When the IOC said this policy would apply to all their events I asked Ms Coventry if that includes the Youth Olympics. It does, meaning girls as young as 15 will have to take sex tests.
She said: "We really went above and beyond, I think, talking to a lot of different athletes, around how the process should be followed and what does that look like, and the support networks that need to be in place."
For Semenya this just adds to safeguarding issues: "Testing a girl, a child, it is harmful and it is shameful," she said.
Will the rules stand up to a legal challenge ahead of the 2028 Los Angeles Olympics?
While Semenya says she is fighting for the dignity of women, the IOC insists this is about protecting the safety and integrity of women's sport but could need to produce more evidence.
