Six former detainees at Guantanamo Bay have won their legal battle to have their claims against the Government heard in public.
In a far-reaching judgment on the principle of open justice, the Court of Appeal yesterday overturned a previous ruling which would have allowed MI5 to use secret evidence to defend itself against claims it was complicit in unlawful detention and torture.
Last year, the High Court ruled that there was no reason in law why the court could not allow a "closed material procedure" to be used in a claim for damages.
This would mean that the Government and the secret services would not have to disclose information to the claimants' lawyers if they felt that doing so would damage the interests of national security, the UK's international relations, the detection and prevention of crime, or was likely to harm the public interest in some way.
It was proposed that any sensitive material would be disclosed to "special advocates" - barristers who had been given security vetting and clearance but who could not discuss the evidence with the six claimants.
But yesterday the Master of the Rolls, Lord Neuberger, said the court would "take a stand" against secrecy that the judges said would undermine the "most fundamental principles of common law".
The six detainees were arrested by the Americans and foreign security services after the 11 September attacks and then held at detention camps in Afghanistan, Morocco and Gambia before finally being transferred to the US naval base in Cuba.
Lawyers acting for the Government had argued that the men's claims for damages included allegations which touched on matters of national security, which meant the cases should be heard in secret. But Lord Neuberger, sitting with two other senior Court of
Appeal judges, said that no civil hearing could be heard in secret because the courts had not been empowered by Parliament to withhold evidence from the claimants.
Lord Neuberger said: "In our view, the principle that a litigant should be able to see and hear all the evidence which is seen and heard by a court determining his case is so fundamental, so embedded in the common law, that, in the absence of parliamentary authority, no judge should override it. …