A survey of 5,000 people found 82% backed peer Lord Falconer's Assisted Dying Bill which would allow people to end their lives early if they are terminally ill.
It found among Christians the approval rating was 80%.
The Bill, if approved, would allow doctors to prescribe a lethal dose to patients with less than six months to live.
The Assisted Dying Bill ran out of time to be voted on in the last parliament but Lord Falconer said he will bring it forward again after the election.
But critics say it is playing God and many people can live longer than doctors predict.
In the Populus survey, carried out for a pro assisted suicide organisation, 45% said they would be willing to break the current law and help a loved one to die, despite risking 14 years in prison.
53% said they would think more positively about an MP who supported assisted dying, according to the poll.
In February a poll for an organisation in favour of assisted suicide found that 78% of the Scottish public back legalising the practice.
At the time Dr Peter Saunders, a Christian from the group Care Not Killing, said polls were "easily manipulated" and that "public opinion is uninformed, uncommitted and unconvincing".
"Public support for a similar Bill dropped dramatically from 73% to just 43% when the five key arguments against it were heard," he said.
"Polls consistently show between 70% and 80% in support of assisted suicide. However, the issue is clearly far more complex than a simple 'support'/'oppose' question can do justice to.
"When offered evidence about the nature or source of opposition to assisted suicide, and some of the key arguments against it, this high level of support rapidly dwindles."