The UK government's former health tsar has told headteachers pupils should not be referred to by their sex because there needs to be a move towards more gender neutral language in schools.

Natasha Devon said that it was "patronising" to walk into an all-girls school and refer to the pupils' gender and such neutral language should also be used with boys. It was also important not to exclude transgender pupils, she added.

Using the term 'girls' can cause children and teenagers to feel anxiety as they would feel that they would have to do everything perfectly. Meanwhile male pupils may feel that being called 'boys' means that would feel pressure to being "macho...being told to man up".

"I don't think it is useful to be constantly reminded of your gender all the time and all the stereotypes that go with it," she told the Girls' School Association's annual conference.

"I think actually in some ways boys are more constrained by the expectation of their gender...and whilst that is being challenged and changed I don't think it's helpful to keep saying 'girls, girls, girls, boys, boys, boys', because there is so much implication that potentially goes with that."

Devon was appointed mental health champion for schools in 2015 before she was fired after she criticised the government. She said that another reason not to use gendered terms like girls or boys is because there may be transgender people in the room.

"There are some schools I go into that are single-sex schools, but there are transgender students in the year," she added.