11/08/2017 08:43 BST | Updated 11/08/2017 08:43 BST

Lord Neuberger's Salutary Warning

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Lord Neuberger, the retiring President of the UK Supreme Court, has issued a salutary warning. On 8 August 2017 he told the BBC: "If [the government] doesn't express clearly what the judges should do about decisions of the European Court of Justice (ECJ) after Brexit, or indeed any other topic after Brexit, then the judges will simply have to do their best." He added: "But to blame the judges for making the law when Parliament has failed to do so would be unfair." And: All judges "would hope and expect Parliament to spell out how the judges would approach that sort of issue after Brexit, and to spell it out in a statute."

For a judge actually to request parliamentary guidance in this way is unusual, to say the least - and more than welcome. The government should sit up and take notice of this salutary warning. Because, what Lord Neuberger is saying is that, without specific guidance spelt out in a statute, judges would be forced to make up the law themselves.

Making law is legislation, which is reserved to Parliament. And the sovereignty of Parliament is the most fundamental principle of the British Constitution. The judges' role is to interpret and apply the law, not to make law themselves. But, if left to themselves, the judges will make up the law on the hoof, as has unfortunately happened all too often in recent years. Here are a few examples:

• Prevention of a number of deportations by misinterpreting Article 3 of the European Convention on Human Rights.

• Leaving it up to the courts to decide whether to recognise prenuptial agreements - by contrast with the United States and most European countries, where "prenups" are automatically valid, mostly as a result of legislation.

• The judges have been forced to step into the breach as a result of the failure of Parliament to codify the common law - by contrast with most states of the United States.

Lord Neuberger's exhortation of parliamentary guidance is not confined to how the courts should treat decisions of the ECJ after Brexit but extends also to "any other topic after Brexit". This ties in with another of Lord Neuberger's salutary reminders, with which he ended a recent speech in Oxford. He pointed out that "a safeguard against judicial law making which is subsequently thought to be wrong exists in the fact that, where the law has been developed by a judge through a decision which is thought to be inappropriate, Parliament can always reverse the decision by legislation. And, in a speech concerned with the role of judges under a a constitutional system based on Parliamentary sovereignty, it is perhaps appropriate to end with a reminder that any judicial decision can be revoked by Parliament through a statute."

Revocation, i.e. cancellation, of any court decision by Act of Parliament? Yes, indeed. This nuclear weapon in the hands of Parliament, and therefore in practice in the hands of the Government, was last used in 1965, when the War Damage Act was passed by Parliament to revoke the decision of the House of Lords (as a court) in Burmah Oil v. Lord Advocate (1964). Many recent bad court decisions cry out for revocation, but I wonder whether the current British government is even aware of the existence of this nuclear option, let alone courageous enough to use it.