Managers fear that health secretary Alan Milburn's decision to combine the top jobs at the NHS Executive and Department of Health signals a further tightening of control, ending the arm's-length role of the Executive.
But while the NHS fears a civil service takeover, some managers welcomed the move to make the new chief executive responsible for public health and social care as well as the health service.
Mr Milburn said: 'This new post is at the cutting edge of health and social care reform. The task is to drive through a modernisation programme to create 21st-century health and social care for the people of this country.'
The salary offered is rumoured to be at least£200,000, nearly double that of outgoing NHS chief executive Sir Alan Langlands.
John Restell, First Division Association NHS officer, said: 'We have known for some time that the NHS Executive was not long for this world in this shape or form, due to desire on the part of ministers to bring it into the department's work and centralise control.'
Professor Brian Edwards, former director of Trent region, said: 'We have to be clear, is the government's longterm plan centralisation or power to primary care trusts?'
'The government was 'strong on policy but weak on implementation', he added, but 'permanent secretaries and ministers cannot lead the NHS'.
Peter Griffiths, director of the Health Quality Service and former NHS deputy chief executive, warned: 'There is clearly a risk of politicians taking over the day-to-day running, but the right people would want to renegotiate the accountability of the job.'
But he said changing the top jobs could be a step forward for the NHS.
'One of the peculiarities of the current arrangement has been the split between permanent secretary and chief executive. Re-combining them is beneficial if they attract someone of the requisite credentials who can achieve some space between politicians and running the service.'
Fears that the NHS would 'lose its identity' if its leader was also responsible for social care and public health at Whitehall level were raised by one exNHS Executive insider.
'The NHS needs a clearly defined national figure. This person will be responsible for social care, public health and this big additional agenda that is being added to this person's plate. I have never noticed that Alan Langlands is looking round for things to do in his spare time.'
Other commentators felt the move was formalising ministerial control that already exists. Professor Edwards said:
'They are getting rid of any pretence that the NHS Executive ever had any executive powers. It has always been an advisory body to the health secretary.'
Dr Jennifer Dixon, King's Fund senior policy adviser and a former civil servant, said: 'There seems some logic to it. At the moment the permanent secretary has responsibility for the DoH, and the chief executive of the NHS has responsibility for 95 per cent of the resources.'
NHS Confederation policy director Nigel Edwards said the new role would 'bridge the divide' between policy and implementation, health and social care.
'It was always an uneasy situation, never quite clear who was responsible for which. It was easy for policy makers to blame implementers for failure and vice versa.'
But former NHS leaders warned that the job could prove just too big for one person.
An ex-NHS Executive insider who asked not to be named said: 'Alan Langlands' job is already one of the most heavily weighted jobs in Whitehall.
'If you look at the salary scale Sir Alan is well up the league table of permanent secretary jobs, and we are making it even more heavily weighted - there must be concern about the scale of the job.'