LONDON The highest court, the Lords, ruled against the government on Wednesday in a sensitive case involving the use of secret evidence to keep terrorism suspects under surveillance without charge.
Nine law lords unanimously upheld an appeal by three men who argued it was against their rights to be subject to control orders -- a form of house arrest -- based on secret evidence they were not privy to and could not challenge in court.
The decision does not overturn the use of control orders, introduced by the government in 2005 and which allow terrorism suspects to be kept under curfew for up to 16 hours a day, but it does call into question a central element of the policy.
Human rights and justice organisations say the orders violate fundamental rights and freedoms, running the risk of turning Britain into a police state, with suspects under surveillance without knowing what they have done wrong.
Because the orders rely on secret information collected by the security services that cannot be disclosed or used in court, they also presume guilt without evidence being presented and without it being able to be challenged in a trial.
The three suspects' cases -- out of a total of 17 control orders currently in force in Britain -- will now return to the High Court for further consideration. It is the second time the Lords has ruled against elements of control orders.
The government said it was disappointed by the ruling.
"Protecting the public is my top priority and this judgement makes that task harder," Home Secretary Alan Johnson said in a statement.
"We introduced control orders to limit the risk posed by suspected terrorists whom we can neither prosecute nor deport.
"All control orders will remain in force for the time being and we will continue to seek to uphold them in the courts."
Since their introduction, control orders have been used relatively sparingly, with a total of 38 people subjected to them. Seven of those have absconded.
Rights campaigners said the Lords' decision could mark a turning point in the use of secret evidence in control orders.
"One thing is clear from this judgement: it's going to be much more difficult for the government to sustain the use of control orders when they have to disclose the evidence to the suspects," Eric Metcalfe of the group Justice told the BBC.
"Parliament and government have to decide whether they are going to limp on with using secret evidence in control orders or whether they can actually take the bold step of getting rid of it once and for all."
(Editing by Steve Addison)