Campaigners against "right-to-die" legislation, who commissioned the research, urged peers to recognise voters' fears about the move and throw out the plans when they are debated tomorrow.
Proposals by Labour ex-justice secretary Lord Falconer, which would offer the chance of assisted dying to terminally ill patients deemed mentally capable and within six months of likely death, were the subject of a marathon debate in the House of Lords in July.
Among backers were former Archbishop of Canterbury Lord Carey who shocked many by declaring he had reversed his opposition - but the issue remains highly controversial and is set to provoke further fierce discussion.
Yahoo News is reporting on a new UK poll released to coincide with the recommencement of debate on Lord Falconer's 'assisted dying' bill in the UK House of Lords.
The public backs the principle of state-assisted suicide for the terminally ill but has serious concerns that in practice the system would be open to abuse, put undue pressure on the elderly to end their lives and be extended to other groups such as the disabled, a poll found.
Pollster ComRes found that 54% agreed that people "should have the right to end their lives whenever they choose and the state should help them by providing lethal drugs".
But a larger proportion, 58%, accepted that it was "impossible to make the system completely safe from abuse by unscrupulous relatives or others who could influence the process".
The research, for disability rights campaign Not Dead Yet and anti-assisted suicide alliance Care Not Killing which are planning a protest outside Parliament ahead of the vote, found that 48% thought it would put vulnerable people under pressure to end their lives prematurely.
By 41% to 10%, voters thought the change was " likely to increase abuse of the elderly and disabled" and b y 42% to 31% that it would " inevitably be extended eventually to other groups such as the disabled".
Dr Peter Saunders, campaign director of Care Not Killing, said: "This poll brilliantly captures the complexities around this issue.
"While the public remain split on the fundamental issue, it shows that the British people are far better informed than those campaigning for a change in the law would have you believe.
"Those surveyed knew that there is no safe system of assisted suicide anywhere in the world.
"For example, the US state of Oregon, which is the model for this piece of legislation, has seen assisted suicide rates increase by over 400% since its introduction. At the same time, a study of those ending their lives found that nearly one in six were suffering from clinical treatable depression."
"Despite repeated denial by well-financed pressure groups, the public knows what is happening in Holland and Belgium.
"These two countries initially introduced more limited legislation but euthanasia has now been extended to include babies with spina bifida, children with terminal illnesses and adults with dementia."
He said it was "chilling" that one in 10 of those asked said they " agree with the author Martin Amis who thinks elderly people should be rewarded for ending their lives".
In 2010, while picturing a future "civil war" between young people and a growing " population of demented very old people, like an invasion of terrible immigrants", he said: "There should be a booth on every corner where you could get a martini and a medal".
Dr Saunders said: "This highlights the frightening undercurrent of deep prejudice that some people harbour towards the older members of our community.
"If there was any doubt about why it is absolutely vital the current legal protections that prohibit assisted suicide and euthanasia are maintained, then this one fact should be proof enough."
A recent survey of 600 doctors by the Medix consultancy found that 60% are against a change in the law to allow physician-assisted suicide, a rise of 17 points from the last time the same question was asked in 2004.
If Lord Falconer's Bill completes its passage in the Lords, the House of Commons will have the option to pick up the Bill - but this is not certain.
Even if it does reach MPs, the looming general election in May 2015 makes it unlikely the Bill will ever become law in its current form.
:: ComRes interviewed 2,019 adults online between October 31 and November 2.