A group of NHS trusts has been accused of making "short-sighted" plans to introduce regional pay and conditions which would "undermine the national ethos of the NHS".
The British Medical Association (BMA) said the 20 trusts in the South West which plan to fix the pay, terms and conditions of health workers in the region would also waste resources and could make it harder for some areas to recruit high-quality staff.
Proposals put forward include cutting pay and increasing hours.
In a new paper, the BMA describes the measures as "short-sighted", saying they could lead to demoralised staff and an increase in regional variations in quality of care.
Dr Mark Porter, chair of council at the BMA, said: "If this initiative is allowed to go ahead, other regions are likely to follow suit, taking us further away from a truly national health service.
"We do not want to see skills drain away from certain areas of the country, particularly in more remote regions.
"This is a distraction from serious attempts to address the massive financial challenges facing the NHS.
"Instead of wasting resources on short-term measures for which there is no evidence, and that will only serve to demoralise staff, we should focus on ways to genuinely improve efficiency and quality."