Proposing the move at the annual British Medical Association conference in Cardiff, Dr Keith Malone, a junior hospital doctor from Scotland, said an increasing number of doctors had become involved in carrying out death sentences worldwide.

Problem in the US

There was a particular problem in the US, where the death penalty was reinstated in 1977 and where lethal injection was the sole method of execution in 21 states.

While the role of the doctor was usually confined to a pre-execution physical and issuing of a certificate of death , there was evidence that at least four doctors had played a more active role in the execution process in the state of Illanois, where the law was changed to guarantee doctors' anonymity.

Lethal injection was also used in China, where organs from executed prisoners were extracted for organ transplantation.

Dr Judy Gilley, deputy chairman of the BMA GP committee, said she had two asylum seekers receiving care at her north London practice whose husbands had been executed.

"When such a patient sits in my consultation room, can they trust me as a doctor, knowing that a member of the medical profession has been involved in the execution of a loved one?" she asked.

BMA Council chairman Sir Alexander Macara said: "We have to recognise there is a risk that we may be accused of interfering in the domestic affairs of sister medical associations, but my advice would be so be it.

"All that is required for the triumph of evil is that good men and women do nothing."