Government hopes of saving pounds50,000 with every hospital merger are largely illusory, a leading health policy analyst warned last week.

Professor Trevor Sheldon told a King's Fund debate the evidence suggested that while there might be economies of scale with small hospitals, once bed numbers reached around 600 costs actually increased.

Proposing a motion that 'Size doesn't matter', Professor Sheldon accused 'merger mania' of 'eroding the health service, making hospitals temples of high technology with specialists their high priests'.

But the motion was opposed by Professor John Ward of Royal Hallamshire Hospital, Sheffield, who argued that larger hospitals were inevitable as Britain was currently 'grossly under-doctored'.

Professor Ward predicted that the Royal College of Physicians would soon say that there should be no single-handed consultants in major specialties because it was impossible to provide 24-hour, seven days a week, 365 days a year cover in that way.

It was therefore imperative that consultants and junior doctors were grouped together, forcing the development of larger hospitals or the amalgamation of smaller ones.

The motion was carried, with nearly two-thirds voting in favour.