Sex education for schoolchildren under 16 should only include "normal science" of reproduction and chromosomes, Ukip has said as it criticised those "obsessing on gender queer theory".
Ukip education spokesman David Kurten added that it was wrong to suggest that anything to do with "non-reproductive sexual acts, sex-change operations or gender fluidity" should be taught by schools to pupils under the age of consent.
He said such topics could be introduced after a child turns 16 when they are becoming adults and therefore "can deal with these different concepts" and understand them.
Mr Kurten said parents are the primary educators of their children, adding that counselling should be offered to those pupils who want to talk about their feelings and "specific things", those at "risk of sexualisation" at an early age or those who have become sexually active before 16.
Speaking at a press conference in central London this morning, a week before the general election, Mr Kurten said: "We must protect our children from damaging and confusing fringe ideologies which sexualise children at an early age and confuse their natural development as boys and girls – both in primary, secondary and even pre-schools.
"No one would have thought 10 years ago that it would ever be considered politically incorrect to call children boys or girls, to call parents mothers or fathers, or if you say there are two biological sexes determined by your chromosomes rather than 40 or 50 or 60 different genders then this is on the way to being considered a hate crime.
"Of course it isn't. It's science.
"We must continue to teach scientific facts of reproduction and that your chromosomes determine your biological sex – the right age to do this is 11.
"But children deserve a childhood. They should not be sexualised with concepts which are grossly inappropriate for their age."
He added: "While countries in Asia are flying ahead of us in academic attainment and eastern European countries are training their own young people with all the technical skills they need to succeed, in Britain part of the debate about education is focused by obsessing on gender queer theory and whether boys should wear girls' uniforms.
"This is nonsense and we need to focus and lead our young people to what is important – so they have the skills they need to survive and thrive in the 21st century."
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