What seems a logical step may turn out to be impossible to achieve

After 15 years the distinction between the NHS's most senior manager and the Department of Health's most senior civil servant is to be abolished and the post of chief executive combined with that of permanent secretary. The relationship has always had an air of uneasy compromise. Victor Paige - who as chair of the NHS management board was the first to occupy a role broadly equivalent to Sir Alan Langlands' today - famously resigned in 1986, less than halfway through his contract, because of lack of clarity about his jurisdiction. 'There are always others in the action - or trying to be, ' he complained in a reference to civil service 'interference'.

Times have changed. The two cultures are much less starkly divided than once they were. Many an NHS manager has done a stint at the DoH, and a stream of former civil servants have held their own in frontline health service management posts since the mid-1980s. Mr Paige's three successors evidently found it easier to establish an effective modus vivendi with their mandarin colleagues. Today, the desire for joined-up policy-making and management suggests the logic behind putting one person in charge of the NHS, public health and social care, as well as heading a major Whitehall department.

But not so fast. Health secretary Alan Milburn has created a gargantuan job. Can any single individual do it effectively? It is hard to imagine one who would have the personal authority and credibility to hold equal sway over their various fiefdoms. The sense that the NHS alone is such a giant enterprise that it needs an identifiable, accountable manager at its head led to the creation of the chief executive's role. The job description has not diminished in scope.

Inevitably, rumours are circulating that an 'outsider' will be the likeliest choice. They always do whenever the top job is vacant, and ministers in the previous government flirted repeatedly with the idea of installing a charismatic business leader as NHS chief executive. But none with a successful track record would ever take on so gruelling a task. Put your money instead on a civil servant with an unorthodox background or an NHS insider with hinterland, whose CV reveals them to be more than simply a career manager.