By the time the courts adjourn for their next holiday break, we shall know who will be taking two highly influential judicial posts. The UK judge at the European Court of Human Rights (ECtHR) will sit on every case brought against the British government in Strasbourg. The president of the Supreme Court will provide much-needed leadership for judges who are increasingly having to take decisions that politicians would rather avoid.

As I reported last month, three candidates have been nominated by the British government for election to the ECtHR. They are Raquel Agnello QC, Ben Emmerson QC and Paul J Mahoney. Agnello, 48, is described on her chambers website as practising in the fields of corporate and personal insolvency as well as pensions and disciplinary proceedings. Fluent in French and Portuguese, she sits in the High Court as a part-time bankruptcy registrar as well as in the companies court.

There is no formal requirement that candidates have experience in human rights law. However, the parliamentary assembly of the Council of Europe, which elects judges from the three candidates nominated by member states, normally requires at least one of those candidates to be a woman. I had thought that Lady Justice Arden might have been a candidate for the ECtHR but I now see that her husband, Lord Mance, chaired the UK selection panel. He would never have taken this on if she had been interested in the post.

Emmerson, also 48, has 15 years’ experience arguing cases before the ECtHR. A founder-member of Matrix Chambers, he sits as a part-time judge in the High Court and the Crown court. Last December, Emmerson was elected by the UN General Assembly to the panel of judges that will consider outstanding war crimes cases relating to Rwanda and the former Yugoslavia.

Mahoney was born in 1946 and so celebrates his 66th birthday this year. An academic before practising briefly as a barrister, Mahoney was an official at the Council of Europe, which runs the human rights court, for more than 30 years. He was the court’s registrar – its senior staff lawyer – from 2001 to 2005. Mahoney then took his first judicial post, serving as president of the EU civil service tribunal until last October.

A glance at these biographies was enough to persuade me that Emmerson was the frontrunner. But I have now heard that some people are lobbying for Mahoney, presumably on the basis that he might be more conservative than Emmerson. A Conservative MP, Christopher Chope, chairs the parliamentary assembly’s human rights committee and is an ex-officio member of the 30-person sub-committee that interviews the candidates and makes recommendations to the full assembly.

Mahoney is a charming and highly competent lawyer but he would not be suitable for appointment to the court. First, he is too old. Article 23 of the human rights convention says judges must be elected for nine years. But article 23 also says that judges’ terms of office expire when they reach 70. So Mahoney could serve for less than five years – if, indeed, he is even eligible on a correct reading of article 23.

The parliamentary assembly decided ­in 2009 that candidates should not be put forward if they might have to stand aside from individual cases in which they had previously been involved.

It is surely even more undesirable to appoint a judge who must step down halfway through his term. That would also have been Lady Justice Arden’s fate, which is perhaps why she did not apply. (She might prefer a job at the European Court of Justice but I am told that Sir Konrad Schiemann’s successor may be Lord Eassie, a Scottish judge.)

There must also be some doubt over whether Mahoney meets the requirements of article 21, which says candidates ‘must either possess the qualifications required for appointment to high judicial office or be jurisconsults of recognised competence’. Although Mahoney has the formal qualification for appointment to a UK court and has headed an EU court, a career civil servant who helped draft judgments in a UK court would not be regarded as having the independence of mind for appointment as a judge of that court. As for jurisconsults, that curious term is understood to include distinguished academics and practitioners rather than a junior member of the bar who taught part-time.

Meanwhile, the UK Supreme Court is advertising for a president to replace Lord Phillips. It is expected that most of the court’s existing members will be applying, apart from those who are about to retire. What I do not know is whether the master of the rolls has decided to apply; if Lord Neuberger does, I would expect him to get it.

Why might he prefer to stay in the Court of Appeal? Perhaps because the Supreme Court is not a very happy place at the moment. Before the judges moved across Parliament Square, you would never have found the most junior member of a seven-judge panel choosing words like ‘misconceived’ and even ‘aberrant’ to describe the position supported by the president and two senior colleagues. But those terms were used last month by Lord Wilson, ruling on a case brought by veterans against the Ministry of Defence.

Phillips’s last duty is to head the selection commission that will choose his successor, even though he regards that as a bad idea and the Lords constitution committee agreed with him last week. One can only hope he picks somebody the other judges will rally round.