Judicial rulings against ministers have become so common in recent times that it is forgotten how only two decades ago such decisions would have been deemed sensational. It was acceptable then to challenge acts of the executive if they had occurred outside the law (ultra vires) but if legislation were passed that permitted ministerial deeds, even if harsh and seemingly unfair, the prevailing culture was one of judicial deferrence.

That this age is well and truly over is captured by the words of Mr Justice Collins yesterday. It fell to him to rule on a complaint made by five men who have had their assets frozen under measures brought in by the Government to comply with United Nations Security Council resolutions. It is not disputed that the UN Act 1946 allow such edicts to enter British law via an instrument known as an Order in Council. But Mr Justice Collins determined that the deprivation of liberty being suffered by the five whose lives have been affected is of a scale that more explicit parliamentary approval would be necessary. When told that his verdict could leave the Government in breach of its UN obligations, the judge said: “It only has itself to blame for that.”

The executive and judiciary have been at loggerheads across three fields: first, control over sentencing; secondly, the right of bodies such as the Serious Fraud Office to conduct investigations such as that into alleged corruption in the BAE arms deal with Saudi Arabia without political interference; and thirdly, counter-terrorism.

Yet there is a subtle but important difference between these arguments. In the first instance, the judiciary has sought to reduce the power of the executive to influence how long individuals (especially those involved in prominent crimes) should serve in prison on the basis that in most normal democracies this is seen as the exclusive preserve of the courts. That is a valid assertion. Similarly, it is always wrong for the executive to prevent justice from running its proper course by intervening to curtail inquiries, like that of BAE, which might otherwise result in court cases that it would be the duty of the judiciary to oversee.

The realm of counter-terrorism, by contrast, is more murky. Few, surely, would dispute that ministers and Parliament should be in the driving seat when it comes to national and personal security. Judges should not anoint themselves alternative home secretaries. If outrageous breaches of liberty are occurring, the judicial rebuke might be right, but when parliamentary approval has been awarded it should be considered a radical step to undermine ministerial initiatives, not one to be advanced lightly. There is a difficult and delicate balance to be struck between security and liberty, but if judges are seen to be too dismissive of the menace that ministers must strive to meet they will invite derision. The notion that a judge might recast the relationship between the UN, the executive and the legislature at whim is an uncomfortable proposition.

The judiciary was too passive in the 1950s and the 1960s. For too long, the executive in Britain was content to enjoy prerogatives inherited from the monarchy, still exercised in the name of the Crown. The country has moved from an unwritten constitution based on tacit understandings to a semi-written one marked by endless institutional conflict. It is in the interests of all sides to seek to secure an acceptable boundary between them. For if a backlash against either executive arrogance or judicial activism or both were to come, each camp would only have itself to blame for that.