DOCTORS issued a united plea against legalising “mercy killings” for the first time yesterday, before a crucial parliamentary vote that would allow patients to choose when to die.

The Royal College of Physicians and the Royal College of General Practitioners abandoned their neutral stance on euthanasia, after an RCP survey that showed three quarters of the profession opposed a change in the law even for a tiny number of terminally ill people. Among palliative care doctors, 95.4 per cent opposed a change in the law.

But backers of the Assisted Dying for the Terminally Ill Bill believe that the national mood is moving their way, with sympathy for high-profile cases such as Diane Pretty’s attempt to win legal backing to end her life.

The Bill, proposed by human rights lawyer Lord Joffe, would enable adults who are suffering “unbearably” as a result of a terminal illness and are of sound mind to die at their own request.

In practice this would mean that a doctor has to hand them a lethal drug. Doctors are also worried about pressures that the option of assisted dying would put on patients who might feel a burden to relatives.

As lobbying on both sides intensified yesterday, the Bill’s supporters released research by three professors of medical law and ethics arguing that it would lead to fewer assisted deaths.

Professor Sheila McLean, director of the Institute of Law and Ethics in Medicine at Glasgow University, said: “It is clear that the law as it stands is not a sufficient deterrent to doctors who are acting in secret, without accountability and without adherence to safeguards.”

But the Bill, based on euthansia laws in Oregon, is seen as the thin end of the wedge by a formidable array of opponents, who will take the unusual step of forcing it to a vote in the Lords on Friday.

Speakers to oppose it include the Archbishop of Canterbury Dr Rowan Williams and Lord Carey of Clifton, his predecessor. Rather than let the Bill proceed to later stages without a vote, as is usual for a Second Reading, they are hoping for a decisive vote against.

Doctors’ leaders feared that their previous failure to take a position on euthanasia was being interpreted as tacit approval for mercy killing.

RCP Fellows were asked whether they disagreed with the proposition: “We believe that with improvements in palliative care, good clinical care can be provided within existing legislation and that patients can die with dignity. A change in legislation is not needed.”

More than 5,000 responded, with 26 per cent in favour of a change and 73.2 per cent against. Challenged by a minority who felt the question was biased, the college launched a second poll, using — to the fury of some Fellows — a question drafted by Lord Joffe. He expected this to produce a very different result.

This time the question was: “Do you believe that a change in legislation is necessary for the small number of terminally ill patients for whom palliative care does not meet their needs?” Strikingly, this produced from 2,144 respondents an almost identical balance of opinion. While 28.1 per cent favoured a change in the law, 71.3 per cent opposed it — only fractionally fewer than in the original ballot.

GPs did not carry out a ballot but discussed the issue in council and concluded: “The RCGP firmly believes that with current improvements in palliative care, good clinical care can be provided within existing legislation. The College is opposed to any change in legislation.”

Last night Deborah Annetts, chief executive of Dignity in Dying (formerly the Voluntary Euthanasia Society) rejected the RCP ballots as a sham. “This was a narrow and rapid consultation on assisted dying,” she said.

“The College gave its members only 48 hours to respond and hence it is very unlikely that this is representative of doctors’ views.

“The consultation seems to have been run with the aim of achieving a pre-ordained result. It was deeply flawed.

“The most recent major survey of all doctors in the UK showed that nearly two thirds of them feel patients and doctors would be better protected by a more transparent law that allowed patient choice,” she said.