A major part of government legislation to deal with terror suspects has been described as incompatible with human rights laws by a High Court judge.
Ministers have faced criticism over their anti-terrorism legislation
A Briton given a "control order" by Home Secretary Charles Clarke to restrict his movements was denied a fair hearing, Mr Justice Sullivan said.
He ruled it was "conspicuously unfair" that there was no impartial review of the control orders.
The Home Office says it will appeal against the judge's decision.
Ministers introduced control orders for terror suspects it could not prosecute in 2005 after their policy of detention of foreign suspects without trial or charge was ruled illegal.
The man, known only as "S", was stopped at Manchester and Heathrow airports in March last year as officials believed he was trying to go to Iraq to fight against coalition forces.
RESTRICTIONS ON 'S'
Under his control order "S" must:
Surrender his passport
Not possess travel tickets or leave the UK
Not enter airports, seaports or railway stations with international rail services
Reside at a given address and give a week's notice of any change of address
Report to police every day at a set time
Permit the police to enter and search his address at any time
He was the first person to be placed under a control order in September 2005. There are thought to be 11 others subject to similar orders.
Lawyers for S, also referred to as MB, argued that the decision to put him under a control order needed to be reviewed by an independent, impartial tribunal.
The judge agreed, saying the courts "merely review" the lawfulness of the minister's decision "on the basis of the material available to him at that early stage".
Mr Justice Sullivan said this meant their rights were decided "by executive decision-making, untrammelled by any prospective of effective judicial supervision".
"The issue raised in these proceedings is whether the act gives the respondent the fair hearing to which he is entitled. The answer to that question is 'no'."
Although there was nothing technically wrong with the control order, he said the review process revealed the "thin veneer of legality" of the government's anti-terrorism laws.
The Home Office said it did not accept the judge's ruling and defended the Prevention of Terrorism Act 2005, under which the orders are made.
A spokesman said the act "contains rigorous safeguards to protect the rights of the individual, including judicial oversight and reporting and reviewing requirements".
He said the ruling would not force the government to revoke any current control orders, nor would it be prevented from issuing any further orders.
The hearing was the first High Court review of 12 orders.