Schoolgirls are being offered tests for sexually transmitted diseases – during lessons.
The initiative has been introduced at schools in East Sussex to combat Chlamydia, the most common sexually transmitted infection (STI).
But parents are furious because they say their 15 and 16-year-olds are being 'humiliated' after being asked to swab test themselves in school toilets.
Story continues after this video.
The mother of one teenage girl at Blatchington Mill in Hove criticised the initiative, and said her daughter refused to do the test, because she felt uncomfortable about it.
She told the Telegraph: "I didn't know anything about it beforehand and I think the school should have let us know as parents that our children were going to be asked to do this.
"I know the tests were done by the students in the toilets but I think it is humiliating to ask teenagers in class to do a test for an STI."
Tina Daniels, 44, from Brighton, said she was shocked when her daughter told her tests had taken place at Patcham High School.
She said: "I am all for educating our youngsters on sex education issues and for some teenagers these clinics could be beneficial. But I think it's important for parents to be made aware that these facilities are available for their children."
Ashley Harrold, the school's deputy headteacher, said children were spoken to about STIs in a 'personal and social education' lesson and offered the swabs.
He said: "It is an NHS strategy where, to demystify the test, they can have one to take away and try."
A statement from the school said: "As part of the session all learners are offered the opportunity (no one is made to do it) to do a Chlamydia test during the lesson in an effort to normalise taking a Chlamydia test.
"It is not anticipated that a great number of these will return a positive result, it is more an exercise to demonstrate how easy and painless doing one is and to reinforce in their minds how and where they can do the test should they need to in the future."
All secondary state schools in Brighton and Hove except for one Catholic School have signed up to the initiative.
Brighton and Hove Council said the sessions were part of the National Chlamydia Screening Programme, which aims to reduce rates of the infection, which can cause infertility.
More than 200,000 people a year test positive for the infection in England, with 64 per cent of diagnoses among those under 25 years old.
More on Parentdish
Sex education for seven-year-olds
Sex education in school: Pupils 'should be taught about pleasurable aspects of sex'
Sex education: Parents' fury at X-rated images shown in school lesson