By this stage in the game, however uncertain the final electoral arithmetic, a Labour Party hungry for power should have decided on the Butler succession. But does an incoming Labour government even need a Cabinet Secretary who is also head of the Civil Service like Sir Robin? Only if it accepts without demur the Whitehall structure it will inherit from the Conservatives.
There were stories over the Christmas recess to the effect that Labour wants "an outsider" for the post. The fact is that it does not take much networking to see that only a limited number of people in Whitehall and even fewer outsiders have enough experience and clout to become either or both Cabinet Secretary or professional head of the Civil Service. Sir Richard Wilson, now at the Home Office, would be a clone of Sir Robin. If Mr Blair picked Richard Mottram, now at Defence, it could be presented as state-school meritocracy in action.
There are at least four or five of Whitehall's top people who would do the existing Cabinet Secretary job well enough. But their identity matters far less than evidence that Labour has carried out its overview of the machinery of state. Working out in advance which officials of energy and imagination Labour ministers would be comfortable with is important for the government-in-waiting, but it is far less vital than developing a strategy linking political objectives, political possibility and administrative means.
What Labour seems to lack still, oddly, is governing confidence. The kind of confidence that Margaret Thatcher had in 1981 when she summarily dismissed Sir Ian Bancroft as head of the Civil Service. As confident as when she chopped the long-range think tank, the Central Policy Review Staff (CPRS). As confident as when she promoted a committed monetarist to head the Treasury (he is still there).
So far, Labour's preparations have been scant. Derek Foster, the shadow minister covering Whitehall, is marginal to this process. The crux decisions (for example about the relations of Number 10 and the Cabinet Office) are languishing in Mr Blair's pending tray.
Jonathan Powell, Mr Blair's chief of staff, has "had conversations"; he may even have talked to his brother, Charles, Lady Thatcher's Civil Service protege at Number 10. He is said to see himself as head of a revamped "think tank", amalgamating the old CPRS and the Number 10 policy unit.
Some shadows have attended the odd Fabian or Institute of Public Policy Research seminar given by the Whitehall expert Peter Hennessy. But to date the most ordered statement of Labour's thinking about the Civil Service is a watery chapter in Peter Mandelson's and Roger Liddle's bathetic book The Blair Revolution.
Cynical men of the world lean back at this point and say, "committees and machinery, all that is for anoraks". What really matters, they say, are political personalities. If Mr Blair cannot trust his Chancellor, Gordon Brown, as Mrs Thatcher could rely on Geoffrey Howe in 1979, no amount of machinery will bridge the political chasm at the heart of the administration. Splitting the Cabinet Secretary's job, beefing up the Cabinet Secretariat ... all that may be irrelevant, since Mr Blair, evidently, has no Michael Heseltine figure to head a central, progress-chasing unit in the Cabinet Office. Neither John Prescott nor Robin Cook look quite right for the role.
But cynical men of the world are wrong if they don't see how self-defeating is an approach to power that has not worked out, in advance, how far the Civil Service has changed under the Tories and how it ought to change under Labour. Any government with the kind of heavy constitutional commitments that Labour has needs a governing strategy and, critically for ministers who have never tasted life surrounded by a private office cocoon, a realistic sense of what civil servants can and cannot do for a Labour government.
Since January of last year - under more generous rules agreed, to his credit, by John Major - Labour shadows have had reasonably free access to Whitehall. Some have been along to training courses arranged by academic and ex-Civil Service sympathisers at Templeton College in Oxford to acclimatise. Some (David Blunkett and Michael Bichard, the permanent secretary at the Department for Education and Employment) have met and matched. But it has taken some - Frank Dobson, notoriously - 11 months to get round to visiting the man who, if Mr Dobson succeeds to the Environment Secretary's post, will be his daily companion in the pathways of power.
It isn't enough. Just as generals are always fighting the war before last, so Labour shadows seem lost in some ancient perception of Whitehall culled from the pages of the Crossman diaries. Either that or they have been listening too hard to Bernard Donoughue, head of Jim Callaghan's policy unit, and his memories of an obstructionist Civil Service. Folk memories on the left die hard: somewhere here is Ramsay MacDonald succumbing to Lady Londonderry's aristocratic embrace. And if the establishment can corrupt Labour ingenues, so can the smooth mandarins of Whitehall.
New Labourites of the Mandelson stamp think they are too sophisticated to fall into Sir Humphry's clutches. Mr Mandelson, having come to know Sir Robin reasonably well in recent years, thinks all Labour needs to do is give civil servants their marching orders. Just as the machine served the Tories, so it will serve Labour. The old verities about neutrality and objective advice still hold.
The trouble with this is that the old verities are not enough. Mrs Thatcher's handbagging has marked Whitehall, and not just in the sense that there are now executive agencies and contracts and a new management style. Labour will inherit a Civil Service that has lost its intellectual edge and - beneath that infinitely smooth surface - a lot of its self-confidence. And that may actually make things more difficult for a Labour government seeking to initiate radical changes.
There are several areas where Labour will surely need first-rate advice, but will it be on offer. Of all Britain's post-war problems, the one that has never shown Whitehall at its best in terms of the quality of thought or imaginative advice is Europe. And, for all the seminars that the permanent secretaries have organised on the family and social dislocation, social policy is another area where Whitehall is weak, both in terms of inter- departmental co-ordination and new policy ideas.
Labour has at most four months before it takes power. There are two things it can still do before it inherits Whitehall. One is compiling lists. Before taking office, both Prime Minister and Shadow Cabinet colleagues ought to know enough of personnel and potential to identify, where appropriate, Whitehall's good women, French-speakers, Newcastle United supporters and so on.
But the names of civil servants matter less than the job they will be asked to do. What does Labour want Whitehall for? Does it expect hot, expert advice, or just professional implementation of pre-ordained policy? Those are not really administrative questions, they go to the heart of the Labour puzzle. Does Mr Blair want power in order to do, or power in order to be? Modern Whitehall is well fitted to give him the second. For the first, he would need to reform Whitehall far more radically than Mrs Thatcher ever dreamt.