The use of control orders on terror suspects is "justified", but only as a "last resort", the government's terror legislation watchdog has insisted.
Control orders are "proportional", says Lord Carlile
Lord Carlile called the measures, which include restrictions up to near house arrest, a "proportional safety valve for the protection of civil society".
After reviewing 2007 cases he said he agreed with each decision taken by the home secretary to impose the orders.
But the Tories said his report showed control orders were a failure.
Home Secretary Jacqui Smith says control orders, introduced under the Prevention of Terrorism Act 2005, are an important tool for dealing with terror suspects.
Ministers can place terrorism suspects under close supervision with a range of powers that range up to effective house arrest.
In his third annual report on control orders, Lord Carlile of Berriew QC said: "I remain of the view that, as a last resort (only), the control order system as operated currently in its non-derogating form is a justifiable and proportional safety valve for the proper protection of civil society."
Having analysed the operation of the control order system in 2007, he concludes that he "would have reached the same decision as the secretary of state in each case in which a control order has been made, so far as the actual making of the order is concerned".
The renewal of the 2005 Act and with it, the control order system, is due to be debated in the House of Commons on 21 February and in the House of Lords on 25 February.
Ms Smith said: "The government has no higher priority than protecting the public from terrorism.
"Control orders remain an important tool to deal with suspected terrorists who cannot be prosecuted or deported.
"The Prevention of Terrorism Act 2005 strikes the right balance between safeguarding society and safeguarding the rights of the individual."
But shadow home secretary David Davis said Lord Carlile's report showed that 15 out of 31 control orders were absconded from.
In many cases, Asbos or civil law suits may be more appropriate and intercept evidence could be used to lock up "dangerous terrorists", he said.
"The government should have taken the time offered to them by the opposition, to devise a better mechanism than control orders which appear to be consistently failing from both a judicial and security point of view," he added.