In 2019, while competing on the men’s team, Thomas began to medically transition, taking testosterone blockers and oestrogen. Although her swim times slowed considerably, she is still a top competitor in several women’s events, raising questions about the role of testosterone in athletic performance.

This month the governing body, USA Swimming, unveiled new guidelines which include a more stringent threshold for athletes’ testosterone levels – widely seen as making it harder for Thomas to be able to compete in major meets.

This is not the first time Mr Morrison has weighed into the transgender debate. Responding to a report that teachers were being trained to identify potential transgender children in the classroom, he tweeted: “We do not need ‘gender whisperers’ in our schools. Let kids be kids.”

The controversy prompted a transgender child Evie, 13, to confront him on Australian talk show The Project.

“I’m Evie, I’m 13, and I’m a transgender kid, and this is what I want to say to the Prime Minister,” she said.

“There are thousands of kids in Australia that are gender diverse. We don’t deserve to be disrespected like that through tweets from our Prime Minister.

“I went to a Christian school where I had to pretend to be a boy and spend weeks in conversion therapy,” she said.

“We get one childhood and mine was stolen from me by attitudes like this.”

Asked to respond to the emotionally charged statement, Mr Morrison said: “I love all Australians, whatever the background they come from.”