This verdict makes perfect legal and political sense

One of the key principles of Anglo-Saxon law is the separation of powers among the legislature, the executive and the judiciary. In theory, Parliament makes the laws, the Home Secretary enforces them and the judiciary decides whether they have been violated and, if so, what the punishment should be. Unfortunately, real life is never so neat, and for some time the Home Secretary has had the power to refuse to release convicted murderers after their recommended minimum sentence (the "tariff") has been served and parole boards have advised they are no longer a threat to the community.

One of the key principles of Anglo-Saxon law is the separation of powers among the legislature, the executive and the judiciary. In theory, Parliament makes the laws, the Home Secretary enforces them and the judiciary decides whether they have been violated and, if so, what the punishment should be. Unfortunately, real life is never so neat, and for some time the Home Secretary has had the power to refuse to release convicted murderers after their recommended minimum sentence (the "tariff") has been served and parole boards have advised they are no longer a threat to the community.

The justification for this exception has been that the public needs to have confidence that it is being protected from people whom it perceives to be dangerous or whom it just wishes to see punished longer. Myra Hindley is the usual example given, but her case is not covered by this judgement, as she has a "whole-life tariff". The alternative (and rather wiser) argument is that since politicians crave popularity, prisoners demonised by the media will struggle to win release.

The latter point was accepted yesterday by the European Court of Human Rights in its decision to overrule Jack Straw's refusal to release Dennis Stafford in 1997, despite a Parole Board recommendation to do so. The main objective, the court pointed out, is to protect citizens from arbitrary detention outside the rule of law.

There will be the usual explosions of irrational anger that this decision puts a foreign court above the heads of elected government ministers. It should be remembered, however, that the European Convention on Human Rights, on which this judgment was unanimously based, was put into British law by a British Parliament. There is nothing extra-constitutional or extra-territorial about it.

In fact, although they won't admit it, the judgment relieves politicians from facing orchestrated campaigns to use their powers to interfere in the administration of justice. David Blunkett, the current Home Secretary, should be quietly celebrating this sensible removal of a power he neither needs, nor should wish to exercise.