Doctor revalidation will do nothing to find or stop poor-performing doctors, a poll of more than 5,600 doctors found.
More than 67% of GPs and 80% of hospital doctors said there were certain doctors they would not want to treat their friends and family.
The survey, exclusive to the Press Association, was filled out by more than 4,600 secondary care doctors and 1,000 GPs.
When GPs were asked whether revalidation would help identify and deal with doctors who are not fit to practice 32% disagreed and a further 28% strongly disagreed.
Only 16% of GPs believed that revalidation would help root out doctors who are not fit to practice.
Among GPs, 46% did not think revalidation would help them maintain a good standard of practice, while only 28% agreed it would.
The survey was released before the anniversary of serial killer Harold Shipman’s death on Monday.
Shipman was jailed for life in January 2000 for murdering 15 patients while working in Greater Manchester. He was found handing in his cell in Wakefield Prison in 2004.
An official report found that he killed between 215 and 260 people over a 23-year period.
Dr Mark Porter, chair of BMA Council, said: “The revalidation system was never designed to catch criminals like Harold Shipman and its introduction was talked about well before his heinous crimes were revealed.
“Instead, revalidation is intended to encourage lifelong learning amongst doctors and lead to a culture of positive professional improvement throughout a medical career. Many doctors have been frustrated by the implementation because heavy workload and financial pressures in the NHS leave little time and space for the reflection and quality improvement that revalidation promised.”