Confidence among GPs that the Government's NHS reforms will improve patient care has almost halved since they were first proposed, an opinion poll has shown.
Only around one in eight (12%) now expects health service users to be better off as a result compared with nearly a quarter (23%) two months after the blueprint was published in July 2010.
More than half (55%) said care would not improve, with 33% not expressing an opinion either way in the survey by ComRes by the BBC.
Legislation putting the shake-up into effect finally became law last week after a turbulent passage through parliament that saw it significantly rewritten amid hostility from many health professionals.
But ministers are braced for a continued battle as the measures - which include putting control of up to £80 billion of commissioning into the hands of local consortia of GPs from April 2013 - are put into effect.
The poll of 814 GPs showed 83% also feared financial pressures will lead to more rationing of care.
Dr Laurence Buckman, chairman of the British Medical Association's GPs committee, said: "If those who will have to deliver the latest health reforms are unconvinced and reluctant, the Government should take notice of what they say," he said.
Shadow health secretary Andy Burnham said: "Any hopes he had that the concerns of NHS professionals would now subside are blown out of the water by this. Instead, GPs are clearly worried about the future of the NHS, warning of longer waits, service rationing and creeping privatisation.
"Many will lay responsibility for these things directly at the Prime Minister's door."
The poll interviews were carried out between March 21-30.