Doctors' leaders have toned down support for 'superhospitals' serving populations of up to half a million people.
They have admitted that 'for the foreseeable future' the district general hospital 'will continue as the basic unit providing the majority of emergency and elective services to communities'.
A report by the Joint Consultants Committee on the future of acute services recommends that 'superhospitals' serving populations of up to 500,000 should be the 'preferred model'.
But the JCC, which brings together the medical royal colleges and the British Medical Association, says district general hospitals serving between 200,000 and 300,000 people will not disappear.
Instead small units should work closely with other nearby services 'so that strengths can be shared and weaknesses lessened', often by combining management arrangements. 'Where possible' DGHs should merge with other local hospitals to form a single acute general group 'able to offer a more comprehensive and sustainable clinical service'.
But if hospitals merge, accident and emergency departments may have to close, the report warns.
The consultation document, Organisation of Acute General Hospital Services, updates a report produced last year by the BMA, Royal College of Physicians and Royal College of Surgeons.
The original report argued that many hospitals might have to lose their A&E departments and that acute medical and surgical services should be concentrated at fewer, larger centres. The latest report includes the views of all acute specialties.
It backs small hospitals in remote areas, serving 200,000 people or fewer, while saying more work needs to be done to ensure obstetric services are safe.
JCC chair James Johnson says in the report that the public is 'ambivalent' in wanting high standards but opposing hospital closures.
'Frankly the two ambitions are incompatible, but planners need to remember the importance to the community of local hospitals; their significance in this respect should not be lightly dismissed.'
Mr Johnson says that hospital mergers should not mean closing one location: 'Hospitals do not always need to exist on one site, however administratively tidy that may seem.'
And no political party would close 'a third of hospitals in the UK', he adds.
NHS Confederation policy director Nigel Edwards said the document had been produced in a 'policy vacuum' and was too focused on present medical education and training needs.
'More thinking is needed about what the future will look like. It assumes there will be many more doctors and fewer hospitals, but there is no recognition that things may be different.
'Consultants may not be based in hospitals but in primary care. Today it is still the case that a large number of people in hospitals do not need to be there.'
Organisation of Acute General Hospitals. Joint Consultants Committee, BMA House, Tavistock Square, London
WC1H 9JP. Free.