London, England - A group of teenage Christians have been banned by a secondary school from wearing "purity rings" as a symbol of their religious belief in chastity until marriage.
At least one of the dozen pupils, who all attend the same girls' comprehensive in Horsham, West Sussex, is considering legal action against the Millais School for "a breach of human rights".
Although the school allows Muslim and Sikh pupils to wear headscarves or kara bracelets as a means of religious expression, the purity ring - a small band of silver engraved with a Biblical verse and worn as a declaration of abstinence from sexual relations - is not allowed because it is considered to be jewellery.
Lydia Playfoot, 15, who started wearing her purity ring to the school in June 2004, described its policy as "really unfair".
"My friends and I have had detentions and been taught in isolation for wearing the ring," she said. "I feel like I've been treated the same as someone who is caught bringing cannabis into school."
The increasing popularity of The Silver Ring Thing, an American Christian movement that launched in Britain in 2004 and promotes abstinence before marriage, has encouraged a growing number of adolescents to make a "pledge of chastity".
The movement's followers wear a silver ring to demonstrate their commitment. More than 20,000 teenagers have signed up at roadshows in America and Britain.
Staff at the Millais School insist, however, that the uniform dress code stipulates that no jewellery is to be worn, other than a small pair of ear studs.
Lydia said that her ring was more than a "trivial" accessory. "My ring is a symbol of my religious faith," she said. "I think, as a Christian, it says we should keep ourselves pure from sexual sinfulness and wearing the ring is a good way of making a stand.
"I stopped wearing the ring because it was being made really difficult for me. I am sitting GCSE modules this year and I missed loads of drama lessons because the teachers would teach us in isolation.
"Some of my friends are still wearing the ring but they're getting detentions and a lot of hassle.
"I think it's really unfair because in the school code of conduct, it says that you're not allowed to wear hats or scarves, but the Muslim girls get to wear their headscarves to school and they get to wear trousers in PE.
"If I'm not allowed to express my faith, it's a human rights issue."
Her mother, Heather, 47, a housewife, said that she and her husband, Phil, 49, a minister in a non-denominational church, had approached the school on their daughter's behalf.
"We were told that it was a health and safety issue and that the school has a no jewellery policy," she said. "The school's concern was that, if Lydia fell and put her hand out to stop her, it could cause injury. It is obviously discriminatory and absurd."
The Playfoots are now considering legal action. The dispute echoes the case of Shabina Begum, a 17-year-old Muslim, who was excluded from Denbigh High School in Luton for wearing a jilbab in contravention of uniform regulations.
She took the school to the High Court two years ago, claiming that the staff had contravened her right to manifest her religion. Judges at the House of Lords eventually found in favour of the school earlier this year after two appeals.
A spokesman for the Millais School said: "The school is not convinced that pupils' rights have been interfered with by the application of the school's uniform policy. The school has a clearly published uniform policy and sets high standards in this respect."