Leading doctors have declared their opposition to proposed legislation which would allow patients to choose when to die.
The Bill will address the options for the terminally ill
A Royal College of Physicians poll found 73% were against a law change.
The Royal College of GPs has also altered its previously neutral stance after members spoke out against new legislation.
The House of Lords will debate Lord Joffe's controversial assisted dying Private Member's Bill on Friday.
Both royal colleges said better palliative care, not a law change, would help the terminally ill most.
Lord Joffe's Bill seeks to make it legal for doctors to prescribe drugs that a terminally-ill person could take to end his or her own life.
Five thousand doctors responded to the Royal College of Physicians poll.
Call for better care
A spokeswoman said: "Irrespective of whether the present Bill is enacted or not, it should be seen as a further signal to campaign for better dying for patients.
"This should include an extension of palliative care services and more discussion of end of life issues in the face of changing values, ethnic diversity and technological advance."
The Royal College of GPs' council also concluded that improvements to palliative care were all that was needed.
On Tuesday, 24 palliative care experts signed a letter to the Daily Telegraph said: "We believe medically assisted dying is a bad solution to a difficult problem."
They raised a series of difficulties in allowing people to ask for help in dying, saying prognoses of how long someone was set to live were "notoriously inaccurate", and that a patient should not "offload" responsibility for their death onto another person.
The doctors, headed by Sam Ahmedza, professor of palliative care at University of Sheffield Royal Hallamshire Hospital, added: "We believe the law should protect the vulnerable from the subtle pressure of society, the pressure of feeling a drain on resources and the pressure of feeling a burden on the family."
Supporters of the Bill say doctors should be able to prescribe drugs that a terminally ill person suffering terrible pain could take to end his or her own life.
Deborah Annetts, chief executive of Dignity in Dying (formerly the Voluntary Euthanasia Society), said: "This was a narrow and rapid 'consultation' on assisted dying."
But the RCP said members had four weeks to respond.
All the political parties are allowing a free vote on this issue and if passed the amendment will delay the measure by six months.
A poll published in the Sunday Telegraph earlier this week showed 65% of people agreed that if the proposed law change went ahead, "vulnerable people could feel under pressure to opt for suicide".