Medical leaders have warned that government health reforms are "potentially damaging" for patients and threaten the stability and long-term future of the NHS.
The British Medical Association (BMA) urged the government to carefully consider what cuts and policies it adopted and not to take what it describes as a "slash and burn" approach to healthcare.
The BMA questioned the necessity of reforms amid public spending cuts and feared the planned transformation of the NHS could see cost become a more important factor than the quality of healthcare.
A BMA report said: "There are aspects of the white paper's proposals which have the potential to undermine the stability and long-term future of the NHS."
Health Secretary Andrew Lansley proposes to redistribute much of the multimillion-pound budget currently handled by primary care trusts (PCTs) to GPs and give hospital trusts greater independence.
But Mr Lansley's proposals have already sparked considerable debate, with critics suggesting the changes could destabilise Britain's health service.
Dr Hamish Meldrum (pictured), chairman of council of the BMA, said: "There are proposals in the white paper that doctors can support and want to work with. But there is also much that would be potentially damaging.
"The BMA has consistently argued that clinicians should have more autonomy to shape services for their patients, but pitting them against each other in a market-based system creates waste, bureaucracy and inefficiency.
"Doctors want to build on the founding principles of the NHS, and to maintain and improve services despite the hugely challenging financial climate. However, they can only succeed if they can work in partnership with others in a co-operative environment."