The Supreme Court should sit in larger panels more often, Lord Sumption has suggested, although he recognised that it could lead to fewer appeals being allowed.
He also urged counsel not to allow their commitment to their client “to spill over” into how they treat their opposing advocate.
In a rare interview with the Bar Council’s Counsel magazine, Lord Sumption – who retires from the Supreme Court at the end of the year – said: “My own view, which my colleagues would not necessarily share, is that the court should sit in larger formation more often.
“No litigant should get the impression, even if it is erroneous, that a differently constituted court would have reached a different conclusion.
“We could even sit in banc all the time like the US, although this would require a change of the law to allow for an odd number of justices, and could mean a smaller case-load with a higher threshold for permission to appeal.”
He explained too how the justices work behind the scenes: “We have a conference after the hearing. The junior member speaks first and we go upwards, each giving a mini extempore judgment of three to five minutes.
“Someone may then volunteer to write the main judgment; or the presiding judge may nominate someone to write because they are the acknowledged expert or their mini judgment expressed best the view in the room or because they haven’t done one lately. Justices do change their minds.
“A dissenter can end up winning round the majority and writing the lead judgment. Someone nominated to write the lead judgment may end up dissenting.”
Lord Sumption said he did not like dissenting. “I’d much rather be in the majority. But it is the way of things if the institution is working properly that we should only be hearing cases which have at least two plausible answers. There may be three or four.
“We sometimes come up with solutions that don’t correspond to the arguments put to us. Then we have to ask for further submissions. This happens more today because hearings are shorter, and there’s less time to think during the hearings.”
He said he saw “much good advocacy these days” by counsel with high intellect, honesty and a willingness to address difficult points rather than circumvent them.
“It helps, too, if counsel don’t take issues personally. I’ve rarely done a case with as much ill feeling between the parties as Abramovich v Berezovsky.
“But my opponent was outstanding. He pulled no punches but there was never a moment when we couldn’t speak to each other on friendly terms. Advocates shouldn’t allow their commitment to spill over into their treatment of their opponent. It’s juvenile and unpleasant.”
It was announced this week that Lord Sumption will be next year’s BBC Reith Lecturer, delivering five lectures on BBC Radio 4 in spring 2019, outlining the decline of politics and the rise of law to fill the void.
In the series, entitled ‘Law and the decline of politics’, he will argue that politicians have surrendered ground to the courts without always reflecting on the wider implications.
Judges have found themselves making decisions in areas which, in his view, should be settled through the normal course of politics.