British Triathlon is the next sporting body to come out in favour of protecting and promoting women’s competition. There will be two categories of athletes – female and open.

Transgender athletes and males can compete in the open category, but only those born female can compete in the women’s class.

The new policy comes into force in January and replaces the old guidelines set in 2018, which allowed trans women to compete against females if they had suppressed their testosterone. 

'We concluded that triathlon is a gender-affected sport and that means that athletes who were born male have an advantage over athletes who were born female and this advantage is significant in swim, bike and run,' said British Triathlon chief executive Andy Salmon. 'We also concluded that physiological advantages are retained by testosterone suppression.

'The new policy will require two categories - a female category, which will be open to athletes who are female sex at birth, and an open category, which will be open to all athletes, including men and transgender athletes. 

'For international competition, only athletes who are female sex at birth will be eligible to represent Great Britain, England, Scotland or Wales in female competition.

'We believe this is the right policy for our sport in Great Britain. We are incredibly proud and precious about our tradition, and our key principle of gender equity, and that is why fairness in our sport is so important.

'We have taken strong legal advice and believe our policy is legally robust.'

Binary spokeswoman, Kirralie Smith, said it was a sensible decision.

“Bravo to British Triathlon,” she said. “This is a fair, safe and reasonable policy that ensures all athletes can be included in competition.

“This policy is inclusive and allows all people to compete without putting women and girls at a disadvantage. It is time for all other sports to do the same.”