Lord Hoffmann simply elides the notion of making the law with changing it.

The truth is that very little law is completely settled (single decisions even of top appellate courts cannot be treated as finally settling a point in a common law system), which gives the judges a lot of leeway, but it is no fiction to say that where they overturn a common understanding of the law they are nonetheless only declaring the law as it always has been, as they now see it. This is particularly true where the question of law involves a question of construction, whether of statute, contract or other instrument, as in DMG. I assume that the ECJ had no jurisdiction to alter the treaties and other laws that the UK had entered into with Europe without the UK's consent, so in ruling that the UK had unlawfully discriminated against Europeans it must have intended to rule that that was what the UK had always undertaken not to do.

It may be that there is some ultimate appellate power to alter the law in relation to issues of the common law, where on any constitutional view the law was settled (say a continuous line of appellate judgments over several generations of the judiciary), but it is dangerous territory into which to enter. It is a good discipline for a judge who wishes not to follow a line of earlier cases to have first to apply this test: "The earlier judges were always wrong, even if I can understand the pressures which caused them to fall into error". If the answer to the test is "no", then the judge should think long and hard about why it is necessary to alter the law. Many current judges seem blithely to push directly through the second door.

Peter.