Frances Gibb reports in The Times today that Sumption will not take up his appointment before 2012 because he is booked to appear for Roman Abramovich in a case against Boris Berezovsky, a fellow oligarch. The lengthy hearing is scheduled for the autumn and gossip among barristers' clerks puts Sumption's fee as not unadjacent to £10 million.

The story is also in The Lawyer. I think The Times had it first but I will correct this if I am told otherwise.

I first heard this story a couple of days ago. That doesn't count as confirmation because the details suggest to me that I heard it from the same source as Frances Gibb.

I didn't follow it up particularly assiduously because, to be honest, I didn't find it plausible. The seat on the court previously occupied by Lord Saville has been vacant for more than six months. How could it be held open until next year?

It used to be the case that a barrister offered a seat on the bench would take it up immediately. If a deferral was allowed, it was always on condition that the appointment remained confidential.

The reason is obvious: a barrister who is about to become a judge is thought to have an advantage over his or her opponent. How much more must that be so if the barrister will soon be in a position to overturn the decisions of the judge before whom he is appearing?

That is not to say that Mrs Justice Gloster, who is expected to hear Berezovsky v Abramovich, is likely to be intimidated by having a future member of the Supreme Court appearing before her. But how would it look? What would we say if a Russian court allowed one side in a dispute to secure the services of a senior appeal judge?

There seems every reason to suppose that Sumption's opponents will ask the court to refuse to hear him. Mrs Justice Gloster would be wise to grant such an application in order that justice may be seen to be done.

Failing that, as one senior legal figure said, Sumption should be allowed to take the case only if he donates his fee to the consolidated fund — from which judges are paid — and draws a judicial salary instead.

I strongly suspect, but cannot yet confirm, that senior judges tried unsuccessfully to persuade Ken Clarke, the Lord Chancellor, to block Sumption's appointment. They will have even more ammunition now.

If Sumption really wants to be the first lawyer to leapfrog two court tiers since 1949, he would be well advised to return his brief and take his seat. Playing hide-and-seek with the Supreme Court does nothing to enhance its reputation — or his.