The family of a Sikh girl excluded from school for wearing a religious bangle have asked the prime minister to intervene in the matter.
Sarika Singh, 14, and her family delivered a petition to No 10 Downing Street signed by Sikh organisations.
The teenager has been excluded from Aberdare Girls' School since November 2007 for wearing a Kara bangle.
A High Court case in London next week, challenging the school's decision, is expected to take three days.
The petition was signed by 150 Gurdwaras, Sikh meeting places, and other Sikh organisations as well as more than 70 non-Sikh bodies, including civil liberty and anti-racist groups and trade unions.
Speaking in London, Sarika's mother, Sinita Singh, said her daughter's education had been badly affected by the exclusion.
She said: "She had top grades and was doing really well. It has affected her in some good ways but also in a hell of a lot of bad ways.
"She has lost a lot of education and if she had been in Aberdare Girls' School she wouldn't have gone downhill and she would have kept her grades."
Sarika enrolled at Mountain Ash Comprehensive School in the Cynon Valley earlier this year, which is allowing her to wear the bracelet, and she will stay there until the legal process is complete.
Her mother added: "She has gone to a new school and although it is a good school she has gone two years behind.
"There is a lot of stress, worry and panic attacks. It is the build-up of everything.
"This is one of the most important years of her school life with her GCSEs approaching. Let's hope we've raised a lot of awareness and let's hope it never, ever happens again."
Sarika, the only Sikh pupil at Aberdare Girls' School, was excluded in November, after being taught in isolation for two months.
The school bans girls from wearing jewelery other than wristwatches and plain ear studs.
The governors rejected her request to
wear the bangle after a "significant period of research" examining the
uniform policy and human rights legislation in detail.
Human rights group Liberty claims the school is violating the Race Relations Act 1976, the Equality Act 2006 and the Human Rights Act 1998.
In January, Rhondda Cynon Taf Council told the school's governors it would no longer give them any more support or financial assistance and confirmed this was continuing for the court case.
In the same month, the Welsh Assembly Government published new guidelines for school governors, saying they should take account of religious views and consider whether uniform policy interfered with the right to manifest a religion or belief.
Amritpal Singh of the Sikh Federation said: "The Sikh community are together on this issue."
"We are showing that the Sikh community are looking at this and that nobody should have to suffer discrimination that Sarika has suffered."