I'm sorry to bang on about the Supreme Court at the moment but it's still the most interesting story in town.

We learned yesterday that the court is likely to be one judge short until January because of the lengthy procedures necessary to choose Lord Neuberger's successor. When judges used to be appointed by the Lord Chancellor, a long-expected vacancy like this could easily have been filled during the two-month summer break.

And it's not as if the new arrangements are any better at producing a more "diverse" judiciary. In practice, senior judges can still choose the candidates they want, just as they could before appointments were made by commissioners.

The interesting question this autumn is whether the vacant seat will go to Jonathan Sumption QC. Though Sumption is regarded as quite extraordinarily brilliant, he has not troubled to spend any time sitting as a full-time judge in the High Court or the Court of Appeal. You can imagine how furious the Court of Appeal judges will be if he is appointed to the Supreme Court over the heads of the entire senior judiciary.

But there is a more serious point here. Sumption has not been tried out as an appeal judge in the UK. However clever he may be, nobody can be sure how good he would be in the job. He couldn't be sacked for poor judgment.

If I were Lord Phillips, I'd advise Sumption to show willing by doing a bit of judging first. 

►On October 19, the Supreme Court will hear a case that's so secret it's listed merely as R(A)vB. Officials thought there was a court order in force that prevented the parties being identified. But I think I can safely report that the case involves a former member of the security and intelligence services who was refused permission to write a book about his work.

He says that this is a breach of his right to freedom of expression. What the Supreme Court has to decide is whether this question should be decided by the High Court or by the Investigatory Powers Tribunal.