Children should not be allowed to “dictate” their gender identity to adults, James Cleverly has said.

The Conservative leadership contender said adults were instead meant to teach children about the world, as their brains are not yet fully developed.

The former minister compared the slow biological development of humans brains with deer, which he said are “pretty much ready to rock and roll” within hours of birth.

Mr Cleverly was asked for his opinion on teenagers socially transitioning without their parents’ knowledge, at a Conservative party conference fringe event.

James Cleverly with his wife Susie (Stefan Rousseau/PA)

He said “childhood, adolescence and puberty is really confusing, hard and difficult” for most people.

The Braintree MP added: “I clearly missed the memo when we collectively decided that children dictate to adults and adults don’t teach children, because that strikes me as a bit of a recipe for disaster.

“We know, and this is not a criticism, it is just a statement of biological fact, human children are born with not fully developed brains.

“It is how we get an animal with a very large skull through the pelvic bone of a woman.”

Mr Cleverly went on: “Other animals don’t have this problem. Deer are born pretty much ready to rock and roll and they are up on their feet within minutes, they are running within hours.

“Humans don’t do that, so this was the biological trade-off that we made through evolution. We have big brains but children are vulnerable and unfinished for quite some time.

“If we lock things in, particularly if we do things which are irreversible medically, because someone who is not yet fully formed is dictating to adults whose job it is in life and society and evolution to protect those as yet unfinished and precious creatures, we are screwed.

“So let’s stop doing that.”

He was earlier asked how he would define a woman, and referred to his mother’s career as a midwife.

Mr Cleverly added: “It is either XY or XX. That is it. That is the bottom line.”