Police escorted children to the school past loyalist protesters
A Law Lord has said the Human Rights Commission "wasted" House of Lords' time over the Holy Cross dispute.
The case was brought by a mother of a child who was a pupil at the north Belfast Catholic girl's school during the 2001 loyalist protest.
She alleged the police breached the child's human rights by not taking a tougher approach with protestors.
Two courts rejected that claim, it went to the House of Lords and that appeal has now also failed.
For four months in 2001, Catholic children and their parents ran a gauntlet of hate on their way to the north Belfast school.
The mother of one of the pupils took legal action against the police - claiming they had failed to prevent her and her daughter being subjected to "inhumane and degrading treatment" and had discriminated against them.
The case went before the House of Lords and five law lords, who published their judgement on Wednesday.
They dismissed the claims and said the police had acted in the best interests of the children.
The police welcomed the judgement and said it demonstrated they they had fulfilled their obligations under human rights law.
The judgement also contains criticism of the Human Rights Commission - which intervened and supported the case.
One of the Law Lords said the commission had "unnecessarily wasted their time" and that its intervention was of "no assistance".
That criticism has been rejected by the Chief Human Rights Commissioner Monica McWilliams.
She said the commission's decision to intervene had been vindicated because one of the Law Lords accepted that it was right when it said the wrong legal test had been used when the case was originally dismissed by the Court of Appeal in Belfast.
Fearghal Shiels, of Madden & Finucane Solicitors, which handled the case, said they were "disappointed by the decision and are giving serious consideration to an application to the European Court of Human Rights".
"It is difficult to reconcile the fact that the House clearly accepted that the children were subject to inhuman and degrading treatment, yet concluded that permitting a protest to take place, which the police admitted was illegal, was upholding the rule of law," he said.