Today the law lords sit to give judgment for the last time in the House of Lords and, as Lord Hope of Craighead said there last week, the upper chamber will be “losing part of itself”. From October the law lords will become Justices of the Supreme Court, created under the Constitutional Reform Act 2005. As the law lords give judgments for the last time, we should celebrate the institution whose life is coming to an end.

The judicial role of the House of Lords had its origins in the wish of early monarchs to delegate responsibilities to trusted advisers. But by the 19th century the appellate jurisdiction of the House of Lords was the subject of ridicule. To reduce the substantial backlog of appeals, a daily rota was imposed on lay peers in 1824 to sit and hear cases.

The Lord Chancellor, Lord Eldon, cynically observed how astonishing it was that peers “looking fresh and lively, excused themselves” on the ground that there might be “fatal consequences” if they were forced to endure “three or four hours’ confinement — unless it was confinement for five or six hours at White’s or Boodle’s at night”. In 1830, Jeremy Bentham, the philosopher and jurist, pointed out that the vast majority of the peers who heard appeals were “ignorant of the law” and “destitute of judicial aptitude, by indolence and carelessness”.

Reform was needed in two respects. First, the Appellate Jurisdiction Act 1876 created a new class of salaried and professional law lords, appointed as life peers, to hear and determine appeals in an efficient manner.

The second reform was that non-judicial participation in appeals was removed. In 1883 Lord Denman, an elderly barrister, tried to vote at the end of a hearing. He was ignored by Lord Chancellor Selborne and by the official law reports. No lay peer has since attempted to vote on a judicial appeal.

Further changes in practice confirmed the distinction between the judicial and other functions of the House of Lords. In 1948 repairs to the building caused by war damage forced the law lords to move their business out of the chamber into a committee room. The temporarily created Appellate Committee became permanent, although the law lords have occasionally sat, as this week, in the chamber, with leading counsel wearing full-bottomed wigs.

By 2005 the law lords had given up any political role. They rarely contributed to debates in the House of Lords and did not vote. Judges no longer gave judgments comparable to the observations of Lord Denning, then Master of the Rolls, in the Court of Appeal in a case in 1976 that “in 1959 Parliament passed the Obscene Publications Act. I remember it well. I attended the debates, and took part.”

In recent years advocates appearing before the Appellate Committee no longer had the experience, which I recall from the 1997 appeal in Thompson and Venables (the young boys who murdered the toddler James Bulger), of being told by the presiding law lord that the hearing would end early that afternoon because one of the judges wished to participate in a debate on an amendment to a criminal justice Bill. In March, however, in the case about whether control orders for those suspected of involvement in terrorism comply with the European Convention on Human Rights, counsel did have the bizarre experience of hearing the division bell summon peers to vote on whether the control order regime should be continued.

For many observers, recognition that the law lords should have no political role was the culmination of the process of transformation of the final court of appeal into an independent institution. But for others, acknowledgement that the law lords were judges whose functions are distinct from those of the legislature was the prelude to the last stage of maturity: the creation of a supreme court outside Parliament.

The matter was resolved by the 2005 Act, which accepted the argument advanced in 1867 in Walter Bagehot’s great work The English Constitution: “The supreme court of the English people ought to be a great conspicuous tribunal” and “ought not to be hidden beneath the robes of a legislative assembly”.

In the past 40 years the judgments delivered by the law lords have placed them in the premier league of world courts with the High Court of Australia and the Supreme Court of Canada. Lords Reid, Wilberforce and Bingham of Cornhill, among others, have commanded respect and admiration for the intellectual force, constitutional perspective and good sense of their speeches.

Not all customers are satisfied: I was once asked by a disappointed client if he could sue the presiding law lord, Lord Keith of Kinkel, for negligence for dismissing his appeal. But in England and Wales (views may differ in Scotland) there is now no serious suggestion — as there certainly was in the early 1960s — that it is an unnecessary extravagance to have a further appeal after the Court of Appeal has given judgment.

I will miss the Appellate Committee of the House of Lords. Its unique atmosphere, a mixture of academic seminar, comfortable club and all-in wrestling match, normally brought out the best in advocates. Its rituals (such as starting at 11am on Mondays, rather than 10.30, so the law lords have time to return from the country) are bizarre but harmless. Who could resist a smile as the presiding law lord leads his colleagues along the corridor, each pausing to exchange bows with counsel before entering the Committee Room?

The death of the Appellate Committee was inevitable, and necessary to give life to a modern supreme court. But for many lawyers, the Committee Room Corridor in Parliament will long echo with the voices heard there: Lord Diplock impatiently asking counsel if that was his best point; Lord Ackner being told by Gordon Pollock, QC, that he should not be sitting to hear contempt proceedings against Tiny Rowland and Lonrho plc because Lord Ackner’s father had been Mr Rowland’s dentist; and Lord Bingham courteously telling counsel at 1pm each day, however feeble their efforts that morning, that their lordships “very much look forward to hearing you again at 2 o’clock”.

The cry of the doorkeepers, John Dryden and Jackie Mouzouros, of “Clear the Bar”, so the law lords can deliberate at the end of the argument, will be heard no more. The Bar and the judges will be cleared out across Parliament Square to the Supreme Court.

As Lord Mance described it, in one of the final speeches by a law lord in Parliament, they will be moving from the Palace of Westminster to the new “Palais de Justice”. But before we lawyers pick up our papers and leave, we should pause to reflect on the end of an era.

The author is a practising barrister at Blackstone Chambers, a Fellow of All Souls College, Oxford and a crossbench peer in the House of Lords. He argued 99 cases before the Appellate Committee of the House of Lords

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