By Nick Assinder
Political Correspondent, BBC News website
Tony Blair's anti-terror laws have been dogged by setbacks and rebellions and the latest ruling by Europe's human rights watchdog threatens to pitch them into further confusion.
Once again, the government has been accused of breaching citizens' rights with its control orders which can see terror suspects virtually placed under house arrest and denied facilities such as telephone calls.
Terror laws face rough ride in Commons
Council of Europe commissioner for human rights, Alvaro Gil-Robles, also expressed concerns over other areas, notably anti-social behaviour orders.
But it is his criticisms of control orders that will threaten to cause the government most difficulty as they chime with the views of many MPs.
Home Secretary Charles Clarke was previously forced into making concessions over his anti-terror laws after detention plans sparked opposition in parliament.
He only got the laws onto the statute books after the prime minister promised to give MPs the chance to review the entire legislation in a year's time.
The new ruling has ensured that will be a hard fought and potentially damaging new row between ministers, backbench MPs and human rights groups.
It is also possible, as predicted by Liberal Democrat spokesman Mark Oaten, that the ruling could now see the government facing court challenges.
Mr Oaten and others have urged the Home Secretary to abandon the entire control order scheme and talk to them about alternatives that, they believe, would be just as effective.
The Lib Dems, for example, have suggested creating an offence of committing acts preparatory to terrorism.
Clarke was forced to concede
The Tories have also expressed reservations about control orders and will also seek significant changes in the legislation.
Specifically, shadow Home Secretary David Davis wants the government to accept the suggestion there would be judicial involvement in any detention orders,
What remains to be seen - and is one of the key questions surrounding the prime minister's pledge of a review - is just how far the government is prepared to go back towards the drawing board.
Downing Street has insisted it believes the laws are necessary to meet the current level of terrorist threat.
And there have been no signs that ministers are set to abandon these tough controls.
But the commissioner's report will only add to the likely political backlash against the legislation and will help set the scene for some difficult Commons battles to come.