Jeremy Clarkson has been criticised by trans campaigners after saying parents "must not be allowed to poison the mind of a child" who thinks he or she is transgender.
In his column in the Sunday Times, he says kids shouldn't be "indulged".
He recounted a story told to him about an eight year-old: "She had been born a boy but had insisted from the age of three that she had a girl's name and wore girls' clothes and, later, that she went to a girls' school.
"Her parents had simply indulged this whim."
Campaigner Paris Lees, who transitioned from male to female herself, says parents aren't forcing their children to be transgender and that many kids attempt suicide after being rejected by their family.
"The overwhelming majority of trans people have had to fight to be accepted by their families," she said.
"I seldom use this word, but saying anything that might encourage parents of transgender children not to support those children fully is evil."
In his column, Jeremy Clarkson also says transgender issues get too much attention in the media and suggests that statistics about the number of people in the UK who want to change gender are wrong.
"[People] have decided that we must now all turn our attention to the plight of people who want to change their name from Stan to Loretta, and fight for the right for men to have babies.
"As far as I was concerned, men who want to be women were only really to be found on the internet or in the seedier bits of Bangkok.
"They were called ladyboys, and in my mind they were nothing more than the punchline in a stag night anecdote."
Paris Lees says comments like Jeremy Clarkson's make it harder for transgender people to be accepted in society.
"Social scorn and rejection is just about the worst thing that can happen to a human being - even monkeys go crazy when rejected by their tribe," she writes.
"At school. At home. In the street. In pubs. In papers. At universities. On telly. Trans people have heard the same... all their lives. 'Your identity is a joke. You're not who you say you are. I don't accept you.'
"I will never, ever understand why some people use their time on this earth to make life more difficult for other people rather than better."
Matt Lucas also weighed in, tweeting: "Batty, transphobic article by Clarkson in The Times today. He's like your out-of-touch grandpa."
Jennie Kermode, the chair of Trans Media Watch, which campaigns for better understanding of trans issues in the media told Newsbeat: "What he says is at odds with the opinion of the vast majority of professionals who work with trans children or on wider trans issues.
"We doubt anyone would take him seriously if we were to comment like this on any other medical matter. Trans children and their parents face many challenges in life, largely due to the prejudice of others. We wish people like Jeremy wouldn't make that harder for them."
The former Top Gear presenter, who was sacked by the BBC last year for punching a producer, is filming a new TV motoring show for Amazon with Richard Hammond and James May.
Radio 2 DJ Chris Evans has taken over from Jeremy Clarkson on the BBC show, which is due on air for a new series in May.