How do we keep judges out of politics? That's not a question you would even ask in the US, where a lawyer with no judicial experience has recently been appointed to the Supreme Court because of her political position. Approving President Obama's nomination of Elena Kagan for what may prove to be a term of 30 years or more, the Senate was divided largely on partisan lines.

They do things rather differently in the UK Supreme Court. Its president, Lord Phillips, said a few days earlier that "unelected judges are better than elected judges". He told reporters: "You are likely to have a more independent stance if you're not looking over your shoulder wondering whether you're going to appeal to your electorate."

Paradoxically, the independence of judges in Britain makes it easier for them to become embroiled in politics. Sir Nicholas Wall, president of the High Court Family Division, wrote a letter at the end of July to the body that administers legal aid, pointing out that its plans for funding child-care work created "a grave danger that the system will simply implode". 

Sir Nicholas cannot have been too concerned when the letter leaked. When he was still Lord Justice Wall last November, he told the Association of Lawyers for Children that it was time for his fellow judges to "come off the bench". In a speech that very nearly cost him his promotion by Jack Straw — a politician, of course — he argued "that as part of the transparency debate, it is for the senior judiciary to speak out in public on issues in relation to which they have knowledge and expertise". 

Provided the judges avoid prejudicing cases that they may have to decide in the future, authoritative judicial criticism of government policies is greatly to be welcomed. Where it starts to go wrong is when junior judges express what appear to be personal opinions on political controversies about which they have no particular expertise.

This summer, seven defendants were cleared of conspiracy to cause criminal damage at a factory in Brighton that helped provide weapons components for the Israeli Air Force. Summing up to the jury, George Bathurst Norman, a deputy circuit judge, described Gaza as a "giant prison camp" and asserted that US support enabled the Israelis to "cock a snook" at anything decided by the UN or the International Court of Justice.