The former Wimbledon champion Martina Navratilova has been criticised for transphobic comments after she argued allowing transgender women to compete in women’s sporting tournaments was “insane and cheating”.

The tennis player first drew criticism from activists and trans athletes when she tweeted in December: “You can’t just proclaim yourself a female and be able to compete against women. There must be some standards, and having a penis and competing as a woman would not fit that standard.”

Under guidelines introduced by the International Olympic Committee in 2016, trans men are able to compete without restriction, while trans women must demonstrate that their testosterone level has been below a certain cutoff point for at least one year before their first competition.