The Hidden Wiring must be unique amongst works on the British Constitution in containing a quotation from the reigning sovereign. "The British Constitution", the Queen apparently declared at one of the author's seminars, "has always been puzzling and always will be". Peter Hennessy's purpose in a series of briskly written chapters on the monarchy,the Prime Minister, the Cabinet, Parliament and the civil service is both to make the constitution comprehensible and to provide rules to codify practices hitherto governed by custom and precedent.
Hennessy's method is seen to good effect in his chapter "The Nolan Inquiry as Ethical Workshop". "The British" one member of the Nolan Committee told him, "like to live in a series of half-way houses". In proposing codes of conduct for MPs and ministers, the committee was offering a half-way house be-tween a system based on convention and a fully codified constitution.
The Nolan proposals exemplify Hennessy's thesis that the behaviour of those in government is coming to be based less on tacit "understandings that are not always understood", in Sidney Low's graphic phrase than on specific codes of practice. We are moving, not towards radical constitutional reform but, in Hennessy's words, "from the back of the envelope to the back of a code".
Hennessy is at his best when dealing with a self-contained and topical subject such as the Nolan inquiry. He is less sure-footed on larger matters such as the Cabinet or the civil service. The chapter on the Cabinet does not discuss some of the crucial factors undermining Cabinet government the weakness of 10 Downing Street vis-a-vis the departments and the difficulties which departmental ministers face in contributing to collective discussion and policy making. The chapter on the civil service does not consider the consequences of the introduction of agencies upon the convention of ministerial responsibility, an issue brought to the surface by the dismissal of Derek Lewis and allegations of undue ministerial interference in the prison service.
Hennessy perhaps exaggerates the consequences of introducing codes of practice, especially, it seems, in resolving the problem of the extent of the royal prerogatives of choosing a Prime Minister and refusing a request to dissolve Parliament. He does not sufficiently appreciate the significance of Peter Clarke's comment, cited as an epigraph to his introduction, that "politics is the final arbiter under an unwritten constitution". When a constitutional crisis arises, it will rarely be resolved by a code.
For the argument will be about the interpretation of the code, or about which code is actually relevant. This argument will be constitutional in form but in reality political, since politicians are likely to frame their solutions in terms of their own self-interest. Thus the outcome is as likely to be determined by the facts of political power as on the basis of an appeal to agreed rules. Therefore constitutional problems cannot be resolved through codes or 'rules of the game'. A constitutional crisis involves, almost by definition, a conflict of constitutional principles, and it is difficult to see how it is to be resolved until it actually arises. For no one crisis is exactly like another. That is as true in a state with a codified constitution as in one without.
Hennessy does not give himself the time to reflect upon such issues. Indeed the general effect of The Hidden Wiring is breathless and rather helter skelter, stuffed as it is with quotations from sources as diverse as Cabinet papers, high-level gossip by politicians and civil servants, and suggestions proffered by the author's students.
He is even generous enough to quote a seminar comment made by the present reviewer. But perhaps Hennessy might have discriminated between the considered opinion of the Secretary to the Cabinet as embodied in a memorandum, and comments made in a seminar discussion in which, surely, the speaker is not on oath before the bar of history!
Hennessy has an unrivalled knowledge of government papers in the Public Record office, and he is an assiduous and determined interviewer of the great and the good. This makes for lively reading. But it is all very much on the surface.
Vernon Bogdanor is Reader in Government, Oxford University and a Fellow of Brasenose College. His book The Monarchy and the Constitution is being published by Oxford University Press in November, and Essays on Politics and the Constitution by Dartmouth in February