The law lords today overturned a court ruling that teenager Shabina Begum's human rights were violated when she was banned from wearing full Islamic dress at school.
Shabina, 17, won a landmark victory last March that Denbigh high school in Luton, Bedfordshire, had infringed her human rights after teachers would not let her wear a traditional jilbab covering her body completely.
Today's judgment was warmly welcomed by headteachers, who feared the earlier ruling would make it impossible to enforce any school uniform policy.
Shabina said she was disappointed, but happy the case was over. She said she would be discussing with her lawyers whether they would apply to take the case to the European court of human rights.
The school, which had agreed a uniform policy with parents and community leaders allowing girls to wear the shalwar kameez (trousers and tunic), went to the highest court in the land last month to ask a panel of five judges at the House of Lords to overturn the ruling at the court of appeal.
Lord Bingham said the school was fully justified in acting as it did.
"It had taken immense pains to devise a uniform policy which respected Muslim beliefs, but did so in an inclusive, unthreatening and uncompetitive way," he said.
"The rules laid down were as far from being mindless as uniform rules could ever be. The school had enjoyed a period of harmony and success to which the uniform policy was thought to contribute."
He said the rules were acceptable to mainstream Muslim opinion. It was feared that acceding to Shabina's request would or might have significant adverse repercussions.
"It would, in my opinion, be irresponsible for any court, lacking the experience, background and detailed knowledge of the headteacher, staff and governors, to overrule their judgment on a matter as sensitive as this," said Lord Bingham.
"The power of decision has been given to them for the compelling reason that they are best placed to exercise it, and I see no reason to disturb their decision."
Shabina had worn the shalwar kameez and headscarf from the time she started at the school at the age of 12 until September 2002, when she and her brother, Shuweb Rahman, announced that the rules of her religion required her to wear the head-to-toe jilbab in future.
Shabina was sent home to change. She did not return to the school and later enrolled at another school where the jilbab was permitted.
The appeal judges had ruled that Shabina was unlawfully excluded when she was sent home to change into school uniform.
Shabina - who missed two years of schooling - said after the judgment was handed down: "Obviously I am saddened and disappointed about this, but I am quite glad it is all over and I can move on now. I had to make a stand against this and I am just happy it is all over now.
"Even though I lost, I have made a stand. Many women out there will not speak up about what they actually want," she added.
She said she would be discussing with her lawyers whether they would apply to take the case to the European court. "I still don't see why I was told to go home from school when I was just practising my religion."
The general secretary of the Association of School and College Leaders (ASCL), John Dunford, said he was delighted that the House of Lords had supported the school. "The school had carried out an extensive consultation with the local community before deciding on the uniform. The purpose of school uniform is to create a community ethos and no individual pupils should be able to go their own way," he said. Mr Dunford added: "This judgment will be widely welcomed by headteachers of schools with uniforms. If the judgment had gone the other way, it would have serious consequences for schools and communities that want their children to wear a uniform." The general secretary of the National Association of Head Teachers, Mick Brookes, said: "This is a good judgment for schools. It shows that where a school is sensitive to local issues and has a good consultative process, its judgment will be upheld in law."
Mr Brookes added: "The balance between the individual rights of a pupil and the need for schools to have order and discipline is always going to be a contentious area."
Alison Carter, a solicitor for the Children's Legal Centre, said the total cost to the Legal Services Commission, which supplied legal aid for Shabina's case going from the high court to the court of appeal and the House of Lords, was no more than £50,000.
The law lords had heard that 75% of pupils at Denbigh high were Muslim and, at the time Shabina was admitted, the headteacher was Muslim.
The faith was represented on the parent teacher association and governing body.
To try to accommodate all faiths, the school adopted the shalwar kameez, a garment worn by many faiths on the Indian sub-continent.
According to the school's lawyers, among Shabina's objections was that the kameez was worn by "disbelieving women".
But Shabina's counsel, Cherie Booth QC, said that was incorrect. Her objection was that the kameez was no longer suitable for her because she had reached sexual maturity and it did not sufficiently protect her modesty.
Lord Bingham said any sincere religious belief such as that held by Shabina must command respect, particularly when derived from an ancient and respected religion.
The issue was whether her freedom to manifest her belief by her dress was subject to limitation and whether that limitation was justified.
He said Shabina could have attended another school, where the jilbab was permitted, far sooner. He was satisfied there was no interference with her right to manifest her belief in practice or observance. Even if there was interference, it was a "proportionate" response by the school.
Agreeing, Lord Hoffmann said there had been nothing to stop Shabina going to a single-sex school where her religion did not require a jilbab or a school where she was allowed to wear one.
Article 9 of the European Convention "does not require that one should be allowed to manifest one's religion at any time and place of one's own choosing", he said.
Shabina's discovery that her religion did not allow her to wear the uniform she had been wearing for the past two years created a problem for her. But her family had chosen that school with knowledge of its uniform requirements.
To change schools might not have been entirely convenient for her, particularly when her sister was remaining at Denbigh high, "but people sometimes have to suffer some inconvenience for their beliefs", said Lord Hoffmann.
"Instead, she and her brother decided that it was the school's problem. They sought a confrontation and claimed that she had a right to attend the school of her own choosing in the clothes she chose to wear."