Police are launching a drink-drive clampdown
The British Medical Association (BMA) wants the government to change the law which prevents them from doing so.
However, the call is likely to provoke disquiet among civil liberties organisations, because it breaches a central tenet of patients' rights.
Samples not for the immediate medical care of the patient have never been taken without consent before.
Consent needed
At the moment, because the unconscious driver has not consented to giving blood, taking a sample for anything other than medical reasons would constitute an assault.
Often, by the time a patient has regained consciousness and can give consent, alcohol levels in the blood will have had time to fall away.
The BMA says that giving doctors the right to take samples in this fashion might help drivers as well as provide the evidence to prosecute them.
Protection and punishment
Dr Michael Wilks, who heads the BMA's Ethics Committee, said: "It is extremely rare for the BMA to advocate taking samples from people for forensic purposes without their consent, but in this case it makes sense to be able to prosecute a drunk driver or establish that the driver was not over the limit.
"While doctors have a responsibility to their patients they also see that there is a clear public interest in being able to prosecute drunk drivers who may have killed innocent people.
The BMA says that samples should only be taken under a fixed set of circumstances.
The blood should be extracted by a senior doctor at the request of the police - and ideally should then be stored and not tested until consent can be gained.
In addition, it says that the results should not be acted upon without the consent of the driver - although refusal to allow results to be used should be a criminal offence.
Doctors, however, should not be forced to take samples against their professional judgement or conscience, it says.