Herbert Smith hit the bull’s eye with its FA Mann lecture this year. So many turned out for lecturer Jonathan Sumption QC that there was no room at Lincoln’s Inn for a number of hopeful, but disappointed, potential members of his audience. Happily, the speech of the Supreme Court Justice-elect is available online. Unhappily, the content has come in for some criticism.

Sumption is a commercial silk with a substantial fan base: ‘the greatest show in town’ is the comment of one respected solicitor. He is famously delaying his elevation to the Supreme Court to dispose of the litigation relating to a £5bn dispute between Russian oligarchs Abramovich and Berezovsky. The Guardian reported his fee as somewhere between £3m and £10m. He is also well known for maintaining his interest in history - the subject of his degree at Oxford and of which he was a don at Magdalen College in the early 1970s. Three volumes of his account of the Hundred Years War are on the shelves; publication of the fourth (planned as the penultimate in a series) is scheduled for 2015.

There should be, therefore, no surprise about Sumption’s forthcoming elevation to the Supreme Court. He might have gone into politics but disliked, according to the Independent, ‘the demands it makes on one’s time’. In any event, it sounds as if he would not have been happy below the cabinet or perhaps even the premiership: ‘There is… a very narrow apex. There is not much of any interest below the top.’ But the bar has done him well and his potential elevation direct from the laity of the bar to the priesthood of the judiciary has been no surprise, except to those who felt that such a translation required a bit more footslogging in the lower courts. That view is widely held by those currently doing their time in the usual way.

Sumption is, thus, fearsomely bright, intellectually restless and accustomed to performing at the highest level. So, it was perhaps predictable that he would choose a key issue for the first public speech made in the shadow of his Supreme Court appointment. And he did - ‘Judicial and political decision-making: the uncertain boundary’. The result was rather curious. The speech could actually have been given by David Cameron who has, of late, been restless under the judicial yoke. Sumption takes a position on judicial review which would have been conservative back in the 1970s.

Sumption’s starting point is that ‘a powerful executive is inherent in the democratic character of the modern state’. In a modern democracy, judicial review is appropriate for questions relating to the application of policy to individual cases but not to the policy itself. That is all very well, but much judicial review concerns how government goes about decision-making - the impact of policy on how individual cases are decided. Judicial review itself was, in part at least, born in the crucible of welfare benefits where lawyers like the late Sir Henry Hodge (as solicitor at the Child Poverty Action Group) successfully prised open how decisions were actually made.

For means-tested benefits, it turned out that cases were nominally decided by the exercise of statutory discretion but actually followed a secret code available only to officials. Politicians were powerless to stop this; judges developed judicial review precisely to do so. As a consequence, a government document in the late 1970s complained that the judges were beginning to require the department ‘not only to act legally but reasonably’. Oh, the horror.

Sumption does not like the development of any concept of fundamental rights that are given particular protection. In particular, he instances offensive developments such as ‘the right of [poor] litigants in person… to bring legal proceedings without paying court fees’. This is probably a reference to a case decided by the Court of Appeal to the effect that, if the lord chancellor wanted to make those on basic benefits pay court fees, he needed statutory authority (ex parte Witham). So far from eroding democratic rights, it actually advanced them.

Sumption’s critique avoids a major point. UK judges may insist that a government gets parliamentary authority but cannot override that authority. Even the Human Rights Act allows only a declaration of incompatibility, which can simply be ignored by the government of the day. It is true that the act has given greater prominence to the role of the Strasbourg court. But, as we can see in the case of prisoners’ right to vote, a government is bound only by its own agreement, not by directly enforceable law, to implement decisions of the European Court of Human Rights.

But proper discussion of this requires a much more subtle account than was offered.

Sumption may, in future, tire of applications to recuse himself by those who argue that his speech shows he will prejudge their hearing. That is why judges, by convention, steer clear of expressing views too clearly. The interesting question is why he would expose himself in this way.

Fellow Gazette columnist Joshua Rozenberg said Sumption had ‘showed a certain naivety’; he may just not have appreciated the constraints of his new role. On the other hand, he is intelligent enough to know exactly what he was doing. Is he staking out a position precisely to appeal to ministers? On the other hand, no one could rattle on about parliamentary sovereignty with as much conviction as Lord Bingham. Ministers learnt to their cost that this was often at his most dangerous. Perhaps, Sumption is going into deep cover. Only time will tell.

Roger Smith is director of the law reform and human rights organisation Justice