What’s so striking about the judicial inquiry into phone hacking is how high-powered it all is. I had initially thought that the lord chief justice would recommend a retired judge for appointment as its chairman. But Lord Judge recognised that the task was simply too important for someone nearing the end of a judicial career. In choosing Sir Brian Leveson, 62, he has selected a lord justice of appeal who is very firmly on the way up.

Like Judge, Leveson was a ‘circuiteer’, a barrister who works in the criminal courts of a particular area. Judge regards Leveson highly and may well see him as a potential successor. If his inquiry is regarded as successful – like Lady Justice Hallett’s inquests into the 2005 London bombings – then Leveson will certainly be a strong candidate for promotion.

But that’s what we all said in 1998 when Lord Saville was given the Bloody Sunday inquiry; it took up the rest of his judicial career. The spectre of Saville looms over Leveson, who knows that his biggest challenge is to keep a potentially open-ended inquiry within reasonable bounds. Unlike Saville, Leveson is not master of his own destiny: he cannot complete the second part of his inquiry – into unlawful conduct by newspapers and the response by the police – until criminal proceedings are completed.

Still, Lord Justice Leveson – not ‘Lord’ Leveson, as he is called by ministers, officials and, inevitably, reporters – has been given an equally high-powered team in support. The government plans to announce today that Leveson has chosen Robert Jay QC as counsel to the inquiry and that Rowena Collins Rice, a career civil servant who qualified as a solicitor in 1995, will be the inquiry secretary.

These two key members of the inquiry team overlapped at Oxford, taking firsts in law in successive years. Jay, 51, was junior counsel to the Crown before becoming a silk. He has much in common with Leveson – which is important because a good working relationship between the chairman of an inquiry and his counsel is important for its success.

In public, counsel to the inquiry appears to be at one remove from the panel he or she is addressing, just like an advocate in adversarial proceedings. In reality, the QC will have worked out the line of questioning with the judge in advance.

But Peter Skelton, writing in Jason Beer’s well-timed new book Public Inquiries (OUP, £125), says that counsel to the inquiry also has a general responsibility to act in the public interest once oral hearings have begun. At that stage, greater emphasis is placed on his impartiality.

During the hearing, a good counsel will read the chairman’s mind and ask the right supplementary questions without the need to be prompted. Counsel to an inquiry has one great advantage over counsel in adversarial proceedings – they can ask a question to which they do not know the answer. There is no risk that an unexpected response will damage their case, since they have no case.

The secretary to a public inquiry is responsible for its timetable, management, premises, website and the production of its report and recommendations. They are normally a senior civil servant – the more senior, the better. When Collins Rice, 51, was chief legal officer at the Ministry of Justice, she held the rather grand title of director general, democracy, constitution and the law. Now at the Cabinet Office, she has been responsible to Nick Clegg for delivering the government’s political reform programme.

Leveson will be assisted by an independent panel – at least during the first part of the inquiry, which deals with the culture, practices and ethics of the press. Its members, in the order they were announced, are: Shami Chakrabarti, director of the campaign group Liberty; Sir Paul Scott-Lee, former chief constable of the West Midlands Police; Lord Currie, former chairman of Ofcom; Elinor Goodman, former political editor of Channel 4 News; George Jones, former political editor of the Daily Telegraph; and Sir David Bell, former chairman of the Financial Times. Since I know three of them quite well I should perhaps make it clear that I have not spoken to any of the six in connection with this piece.

They are a good panel but the gap in their expertise is obvious enough: none of them has worked for a tabloid newspaper. The reason for that is equally obvious: anyone who has worked at the rough end of Fleet Street is likely to have been caught up in the very ‘dark arts’ that the inquiry is investigating. Leveson has been scrupulous about declaring his interests – as chairman of the sentencing council, he had dinner with Rupert Murdoch’s son-in-law, Matthew Freud – and it would not look very good if members of his panel were compromised.

But the Leveson inquiry – there seems no other name to give it, despite the chairman’s natural modesty – could still continue without them. It is quite unlike the inquiry led by Sir Peter Gibson into whether Britain was implicated in the improper treatment of detainees in the aftermath of 9/11.

The detainee inquiry, as it calls itself – ‘torture inquiry’ might have suggested that it had already made up its mind – has three members who take all decisions jointly. Leveson’s panel found that key decisions had been taken before they first met last Thursday.

Still, their task is to assist, not decide. When you can’t trust the press, police or politicians, only a judge will do.