‘I thought my wig a good disguise, but my dentist told me he recognised me immediately.’ Lord Sales is referring to the infamous Daily Mail ‘Enemies of the People’ front page in 2016 in which he was pictured between fellow Divisional Court members, the Lord Chief Justice and Master of the Rolls following their judgment in Miller One.

‘When the storm hit, it felt almost like an out of body experience. My main task that day was to pop to my local newsagent to buy a copy for my scrapbook. Over the next couple of days I felt unusually exposed when walking out in public or travelling on the underground. But others have had personal attacks much worse than that’ and he is grateful to the then Lord Chief Justice, Lord Thomas of Cwmgiedd, for anticipating possible threats and ‘ensuring that heightened security arrangements were put in place to protect us should the need arise’. That said, ‘my main concern was about the legal system – it was appalling that it was under attack in that way.’ He leaves it to others to speak about the ‘decidedly inadequate’ response of the then Justice Secretary to the media onslaught.

As the most recent appointee to the Supreme Court at the time of our interview, Lord Sales was enjoying his ability to speak first as the justices go round the table in reverse order of seniority at the end of a hearing, sharing their views with each other ‘with no debate until the end. The benefit is that you can get your case out without being interrupted. It can be daunting, as colleagues usually listen without expression. Then, by a process of alchemy, the presider picks the justice who is to write the judgment: it’s a matter of who has the time and expertise and who was closest to the consensus view.’

Having been in the firing line in the Divisional Court in Miller One, he found himself in Miller Two after his move to the Supreme Court. ‘Miller Two was an unusual case. The Court is not looking to turn itself into a political actor. Quite the reverse. We would prefer not to be hearing politically contentious claims. A quiet period of reflection would be welcome. But it’s our duty to decide the cases that come before us.’

Why law? ‘There were no lawyers in the family. I never thought of becoming one. I never did amateur dramatics or exhibited thespian tendencies, but I was intellectually curious, worked hard and had strong parental support. I chose English, Latin and history for A level, and – my father being a chemical engineer who wanted me to retain a foothold on the science side – I added maths. Looking back I now see history and maths as a good foundation for legal studies: history because the law moves and develops, especially the common law, and maths because for me it provides a logical structure for thinking about things. Dad was worried I wouldn’t make a living if I did English or history at university. He wanted me to do law as a good basic degree for business; then I could become an accountant; and then a business mogul! I agreed – at least with the bit about law – and by great good fortune I found that I really liked it.’

He studied law at Churchill College, Cambridge. ‘You have to learn a lot before you can start to become imaginative. It can be a shock to the system – all those cases and statutes – until you begin to see the pattern.’ Would he advise budding lawyers to study law at university? ‘If you absolutely love a subject at school and want to study it at university, do so; you’ll be engaged and you can always turn to law later. But if not, my advice would be to study law: it’s a good way of learning how things fit together; and, for those who go on to practise law, you are improved as a lawyer because you get to study a much wider range of topics than just the “core” ones – I still find myself as a judge thinking back to topics I learnt back then, especially constitutional and administrative law.’

Why the Bar? ‘When law clicked with me in my first year I was assuming I’d go down the solicitor route as by far the safer bet. I had a placement at a City firm and liked it but 11KBW approached me and invited me to do a mini pupillage. They were incredibly refreshing and down to earth. I liked the people and could see myself working with them. More to the point, they liked me. I saw that going down the Bar route was the way for me to pursue my intellectual interest in the law itself, particularly public and commercial law.’

His early practice included employment and labour law. ‘These gradually fell away as my commercial and Chancery work expanded and Derry Irvine and Richard Field began to use me frequently as their junior. But I never lost interest in constitutional/admin law, and then I was given “the best job at the Bar” as described to me by Lord Woolf, namely his old job, colloquially known as the Treasury Devil, a principal source of legal advice and representation for the government at the Bar. It was either that or silk, but I knew that I would be in at the start of the Human Rights Act and that the cases would be fascinating. My wife said I was like a kid in a sweetshop when I started.

‘I had thought government as a client would be monolithic but found it was very diverse: each department had its own culture and pushed its agenda, bumping heads with other departments. I had almost an arbitrating role, like the Attorney General. I joked that I had to get a larger table to accommodate the increased numbers of clients attending my conferences.’ He also advised on the creation of the Attorney General’s panels for civil counsel and helped select counsel for the panels. ‘I’ve always been interested in how organisations work’, an interest that was further developed when for five years while a High Court judge he chaired the work of the Boundary Commission for England.

New ground was broken when he took silk in 2006 while remaining as Treasury Devil. ‘I enjoyed being junior counsel and defending the “over-mighty” government against expensive silks, but the judicial appointments system had changed. When I took on the role it was on the expectation that I would go on to the bench immediately afterwards, but under the new system no one knew what to expect. My fear was that I might not get to the bench, but I could be a QC in private practice if needed. It was a rather expensive insurance policy. On the government side we had to discuss whether a QC could be allowed to be Treasury Devil (yes) and then what to call the role. In the end we dropped the word ‘Junior’ from the formal title and I became ‘First Treasury Counsel Common Law’. It was made clear to me that taking silk wouldn’t affect my fees! The job was wonderful but relentless: in court on top cases, advising behind the scenes, a con before court, three or four after, flying by the seat of my pants, needing good juniors. After nine years I was exhausted but I had to wait for the next judicial appointments round, which meant that I probably did a year too long.’

With his intellectual interest in the law, the attraction of the Bench was clear to Lord Sales. ‘I saw the judiciary as an opportunity to leave a thumbprint on something that has been a big part of my life. I had enjoyed my corporate/Chancery work and wanted to continue. So I applied for the Chancery side but I also asked if I could use my public law experience to hear some judicial reviews over in QB. The interview was somewhat of a tightrope walk between the two Divisions, but the Chancellor (Sir Andrew Morritt) was supportive – provided that he could receive the time of a QB judge in return.’

From 2008 the Chancery judge spent up to one third of his time in QB. ‘I liked the combination. Chancery and JR were the two disciplines I enjoyed the most. Chancery was black letter. You could reason yourself through it and come to a particular answer that was right. Public law is conceptually less tightly defined, it’s flexible and open textured, premised as it is on an understanding of how principles should work to produce sensible results, rather than rules. It met my appetite for doing work from a policy point of view. Then I’d feel like being a lawyer again and would be able to go back to black letter law rather than touchy-feely principles.’

The best thing about being a judge at that level? ‘Witness actions, seeing how the facts fit. For example, four people all at the same meeting might have different recollections of it later. The judge needs to understand the documentation and the commercial context, which in turn inform the likelihood of what happened at the meeting. There is then a matrix of probabilities which can be used to test the evidence in the box. Witness actions provide an interesting glimpse into people’s lives. There is no appeal against findings of fact, so the responsibility on the trial judge is great. But I liked deciding cases and sorting out areas of law in my own mind, and fitting the facts into the legal framework. Although the life of a High Court judge can feel solitary – there’s never enough time to test your views with other judges – the upside is that you just have to persuade yourself rather than other judges. When I reached the Court of Appeal, it was challenging but also very helpful to be working alongside other judges who were as involved in the case as I was: debating, testing your own views, trying to persuade.’

The Court of Appeal, which he joined in 2014, ‘was highly collegiate. With three judges debates were fluid; it was easy to chat; there were no high horses. We would normally exchange views for 10-15 minutes before court, perhaps for 10 minutes during lunch. Often we only needed about 10 minutes at the end to decide because of the debate during the hearing itself and all the discussions we had held beforehand. We always knew from the beginning who would write the lead judgment. It was a good way of doing law.’

The Supreme Court is ‘more complex’ because of the greater number of justices hearing a case; but on the other hand ‘you get to work more closely with your 11 fellow judges as individuals than when being rotated in groups of three amongst the 40 or so judges in the Court of Appeal’.

Final advice? ‘Recognise that the Bar is a stressful career: stress can come from the clients and from the need to be a performer. Your arguments need to be succinct, coherent and clear in structure: judges like that. If the court drives you off your thread, always answer the judge’s question at the time it is asked, at least in outline; even if you explain it more fully later, give a quick response now, so the judge can see what your argument is. Follow the pace of the court when it reveals what it is interested in. Temperament is important: don’t lose confidence; retain an inner belief. You are on your own, with responsibility for arguing your cases. If you possess both an intellectual strength and an interest in the law, the Bar remains the best way of combining the two.

The infamous Daily Mail front cover (4 November 2016).