This control order case has been one of the most discussed decisions of 2009. A nine judge Committee gave clear guidance on fair trial principles, which is likely to have a substantial practical impact on future “national security” cases. Perhaps as importantly, the relationship between Strasbourg decisions and their Lordships assessment of the same issues featured strongly.

This case was the House of Lords’ second attempt to articulate the minimum requirements of disclosure that are necessary for a fair trial in control order cases. They had sought to do so previously in the case of MB v Secretary of State for the Home Department [2007] UKHL 46 but since then two cases had forced the issue back before their Lordships.

First, the Court of Appeal in AF  [2008] EWCA 1148, had found it difficult to give practical application to the approach outlined in the ‘enigmatic’ and sometimes inconsistent MB speeches. That Court, and those below it, wanted more clarification. Second, and more decisively, the European Court of Human Rights had made firm comments about the minimum standards of fairness in the case of A v UK (34455/05) 26 BHRCC 1 ECHR (Grand Chamber), when considering the predecessor to control orders (internment of foreign nationals). In light of that judgment it was inevitable that their Lordships would have to review their earlier decision.

For this hearing the constitution of the Judicial Committee also changed. Lord Bingham, having retired, was replaced by Lord Phillips; and the five judge committee in MB was extended to nine. In the end, all nine of their Lordships followed the Strasbourg line.

The result is this: a person subject to a control order must be given sufficient information about the allegations against him to enable him to give effective instructions. He does not have to be given the detail of the allegations or all of the supporting evidence, but he must be given a minimum level of disclosure. Where the material he is given contains no more than general assertions, and the true case against him is based solely, or to a decisive degree, on closed materials, the requirements of fair trial are not satisfied.

The immediate practical effect is that a number of control orders are going to have to be reconsidered very carefully. The (new) Secretary of State has a simple choice. He can either make greater disclosure in relation to the allegations of terrorist activity, or he can abandon his pursuit of the orders. Although the choice is simple, it is not easy. If he does the former, the inevitable question is why was that not done before? If he does the latter, then it is fair to ask whether the control order was ever really needed in the first place?

Individual cases have been remitted back to the High Court for reconsideration and, no doubt, the parties will argue over whether there is a need for more disclosure on the facts of any particular case. As a result, for the men who have been subject of the orders – some for 4 years – there is no immediate end in sight and more appellate litigation seems likely.

In considering this case, it is worth keeping in mind that it is uncommon for nine Law Lords to sit on an appeal, and even more rare  to have all nine in agreement on the result. But control orders are unusual. They test the very outer limits of permissible state power against the individual and raise constitutional issues: How do we define a  state of emergency threatening the nation? Is it permissible to use evidence that may have been obtained through torture? When is an allegation of suspected terrorist activity a criminal charge? What period of daily confinement engages Article 5? There is no shortage of fundamental human rights jurisprudence in this area and it properly merits an unusual degree of judicial attention at the highest level.

Beyond the immediate impact of the decision, the following points are important.

First, while the decision was unanimous the level of true agreement was less clear. Some of their Lordships felt that, even if they did not agree with the controlee’s arguments, the Human Rights Act 1998 required them to follow Strasbourg and find in their favour. Lord Hoffman and Lord Brown, in particular, suggested that had they not been so constrained their conclusions would have been different. This, of itself, is significant. It illustrates that within our constitutional framework our Supreme Court judges will follow Strasbourg, even when they may disagree with it. It is not just UKIP that may be dismayed at that. Lord Hoffman, in particular, appears to view such deference as undesirable. Nevertheless, he accepts that, as a matter of practicality, English judges must follow considered Strasbourg decisions on the same issue.

Second, this decision emphasises that a fair process cannot easily be separated from a fair result. In MB Lord Brown had suggested that there was no unfairness if the Court could be satisfied, on the undisclosed material it had seen, that the imposition of a control order was inevitable. On his reasoning, this would be so, even if the controlee had not had a proper opportunity to meet the allegations. But as Sedley LJ observed in the Court of Appeal, such an approach is flawed. Without a fair process  one can never safely conclude that a control order was inevitable. Perhaps to illustrate that point, during this appeal their Lordships conspicuously declined the government’s offer to view the closed material. The implication was that they could only assess the fairness of the process by putting themselves in the same position as that of the controlee. From this perspective, a fair process is not an annoying obstacle that hinders the government from obtain the right result, but rather as the only proper way of arriving at that result. To put it another way: reliance on due process is not merely of ideological importance, but of practical importance too. Without a fair process you can never have confidence in your conclusions.

Third, even though there is now clearer guidance on fair trial principles, the fundamental criticisms of control orders remain: is it ever appropriate to place citizens under such restrictions, based on no more than suspicion and ‘intelligence assessment’? Many practitioners in this area would dispute that such a process can ever be truly fair. And are control orders really necessary? Somehow other democracies manage to function without them.

Lastly, it is interesting to note the reverence given to the views of Lord Bingham. His position as the ultimate model of the modern appellate judge appears to be beyond dispute. It is clear that in spite of his retirement, his huge presence – with regard both to the content and the style of his judgments – will be a feature in the Supreme Court for many, many years to come.