What does it take to become a justice of the UK Supreme Court?

According to its president, Lord Phillips, those who applied for the most recent vacancies had to demonstrate independence of mind, integrity, intellectual ability, clarity of thought, an ability to work under pressure, social awareness, respect for colleagues, willingness to give talks about the court and a sense of vision.

Notice anything missing? What about judgement? Curiously, this was not a quality that Phillips listed in his speech on judicial independence in February.

There may, of course, have been a good reason for the omission. Those seeking a seat on our highest court would have usually served as judges for 15 years or more.

That would have given them plenty of time to demonstrate whether they have that indefinable sense of what is right and wrong that we describe as ‘having good judgement’. It is not so much about being a brilliant lawyer, more about having common sense.

But, as everyone now knows, one of the candidates for appointment to the Supreme Court did not have years of full-time judicial experience.

Although Jonathan Sumption QC spends a few weeks a year as an appeal judge in the Channel Islands, it is not quite the same as trying cases and hearing appeals year in, year out.

Despite that, it is believed that Sumption was selected for one of the two vacant posts at the court. I say ‘it is believed’ because there had been no confirmation from Downing Street by the beginning of this week – although I reported three weeks ago that Sumption and Lord Justice Wilson had been told they would get the two jobs on offer.

Sumption’s selection – by a panel consisting of Phillips, his deputy Lord Hope and representatives of the three judicial appointments bodies in the UK – is a huge personal achievement.

Leapfrogging two judicial tiers has not happened for more than 60 years, with Lord Reid and Lord Radcliffe being the last two judges appointed to the House of Lords straight from the bar.

But Sumption’s appointment was far from uncontroversial.

It is widely known that this was the second time he applied for a job on the court. Faced with opposition from those who thought the job should go to an appeal judge, the noted historian of the Hundred Years War made a tactical retreat.

This time, brainpower has trumped common sense: Sumption’s supporters – personified by Phillips, as president of the Supreme Court – seem to have defeated his opponents – personified by Lord Judge, lord chief justice of England and Wales.

Attempts to get the lord chancellor to exercise his limited powers of veto seem to have come to nothing.

Nobody denies that Sumption has an intimidatingly powerful intellect, something that counts for a great deal in the judiciary.

But what he has failed to show so far is good judgement.

For one thing, he is still a member of the Judicial Appointments Commission, which selects judges for the High Court and the Court of Appeal.

The commission, which covers England and Wales, does not deal with appointments to the UK Supreme Court. But one of Sumption’s fellow commissioners served on the panel that selected him.

Someone with better judgement might have thought it prudent to stand down.

It gets worse. Sumption has not denied reports that he has accepted a lucrative brief from Roman Abramovich, owner of Chelsea FC, that will keep the QC occupied from October to December this year.

From this we may infer that Sumption has told Her Majesty that he would be happy to accept an appointment to her highest court but not until he has a window in his diary, which regrettably will not occur before 2012.

Sumption does not have many friends on the bench, but it is fair to say that even those who support his appointment are appalled by his decision to take up the post at a time of his own choosing.

Senior judges, sensitive enough about how much more money they could have earned if they had stayed at the bar, are already envious of someone who has made a fortune by deferring the judicial appointment that was his for the asking.

You can imagine how furious they are at hearing that someone who has already made a fortune now wants to earn just a few more millions.

Or perhaps it is more accurate to say that anyone with good judgement can imagine this.

If Sumption knows how the judges feel, he certainly does not care.

The judge who suggested the other day that Sumption should donate his brief fee to the consolidated fund and draw a judicial salary instead was not speaking totally in jest.

Sumption has agreed to represent Abramovich in a case against his rival, Boris Berezovsky.

What would we think of the Russians if their system allowed a litigant to hire a judge?

True, our system of part-time judges allows lawyers to decide cases for or against their professional colleagues.

But that is not the same as a High Court judge having to try a case presented by an advocate who will soon be in a position to declare, with the authority of a final Court of Appeal, that decisions made by the same judge were wrong and must be overturned.

Does Sumption want to remain at the bar? Or does he want a seat on a court that is beginning to lose credibility? He cannot do both: he has to make a judgement.