Terminally ill adults who are expected to die within six months would be able to request assistance to end their own life under proposed legislation for England and Wales.
Two independent doctors would have to be satisfied someone is eligible and has made their decision voluntarily. Requests would also have to be approved by a High Court judge.
Labour MP Kim Leadbeater, who has put forward the bill, said it includes "the strictest safeguards anywhere in the world".
However opponents of assisted dying have raised concerns that people could feel pressured into ending their lives.
The Terminally Ill Adults (End of Life) Bill is due to be published on Tuesday ahead of an initial debate and vote by MPs on 29 November.
It will be the first time since 2015 that the House of Commons has voted on the issue of assisted dying. Back then, MPs rejected proposals to allow some terminally ill adults to end their lives with medical supervision.
If the bill passes the first vote, it will receive further scrutiny from MPs and peers, who could choose to amend it.
A final version would require approval by both the House of Commons and Lords to become law.
The government has taken a neutral stance, allowing MPs to have a free vote on the matter - meaning they can make their own choice and do not have to follow the party line.
Current laws in the UK prevent people from asking for medical help to die.
A separate bill to legalise assisted dying has also been proposed in Scotland.
The bill requires those who apply for assisted dying to:
- Be over the age of 18, a resident in England and Wales and registered with a GP for at least 12 months
- Have the mental capacity to make a choice about ending their life
- Express a "clear, settled and informed" wish, free from coercion or pressure, at every stage of the process
There would have to be a period of at least seven days between two doctors making their assessments and another 14 days after the judge has made a ruling, unless the person's death is expected imminently.
The individual would be allowed to change their mind at any time and no doctors would be obliged to take part in the process.
If all the criteria and safeguards are met, the medication to end someone's life must be self-administered.
It would remain illegal for a doctor or anybody else to end a person's life.
Under the proposed legislation, it would also be illegal to pressure or coerce someone into making a declaration that they wish to end their life.
The offence would carry a sentence of up to 14 years in jail.
Campaigners supporting the bill, including broadcaster Dame Esther Rantzen, argue terminally ill people should get a choice over how they die to avoid unnecessary suffering.
Leadbeater said the current law in the UK was "not fit for purpose" and was "leading to people having horrible deaths, taking their own lives, having to go to other countries if they can afford it".
She told the BBC she hoped MPs would be reassured by the bill's safeguards, adding: "What I would say to colleagues is, if you vote against the bill, or even if you abstain, you’re saying that the status quo is okay and it's not okay."
Groups who oppose changing the law say vulnerable people could feel under pressure to end their lives for fear of being a burden on others and that the focus should be on improving palliative care.
Dr Gordon Macdonald, chief executive of Care Not Killing, said: "The safest law is the one we currently have."
"This bill is being rushed with indecent haste and ignores the deep-seated problems in the UK’s broken and patchy palliative care system," he added.
Health Secretary Wes Streeting, who has said he will vote against the bill, is among those who has raised concerns, saying end-of-life care is currently not good enough to give people a real choice.
In response to such fears, Leadbeater said: "This is not about either improving palliative care or giving people the choice at the end of life that I believe they deserve.
"We have to do both, and they have to run in parallel."
The MP for Spen Valley said there would be "checks against coercion or pressure" at every stage, as well as a code of practice and "robust training" for doctors involved.
She added that if the bill did become law, there would also be a "period of implementation", which would most likely be up to two years.