GPs have been urged to tell the DVLA about any patients who continue to drive when they are medically unfit to do so.
The General Medical Council says it is strengthening its advice after hearing from GPs who are worried about reporting patients to the driver licensing agency.
The draft guidance, which is currently out for public consultation, says public safety should come before patient confidentiality and consent in such cases.
The guidance also emphasises that when doctors diagnose a patient's condition, or provide treatment, they should keep the patient's ability to drive safely at the forefront of their minds.
Figures from the DVLA show there were nearly 160,000 notifications of drivers being unfit to drive, up from just over 125,000 four years previously. These figures cover notifications from police and drivers themselves as well as individual drivers.