The Assisted Dying Bill has been backed by MPs in the House of Commons.
The bill, officially called the Terminally Ill Adults (End of Life) Bill was proposed by Labour MP Kim Leadbeater and has passed the first stage of the legislative process by a vote of 330-275.
Under the bill, mentally competent, terminally ill adults in England and Wales who are assessed by doctors to have six months or less left to live would be allowed the right to choose to end their lives with medical help.
Those in favour of the bill say it is about shortening the death of those who are terminally ill and giving them more control.
But opponents say vulnerable ill people may feel they should end their lives for fear of being a burden to their families and society, rather than for their own wellbeing.
Others expressed concern there had not been enough time to consider the bill before voting.
Christian MP Danny Kruger spoke passionately against the bill, saying it amounted to a "state suicide service", while others urged the importance of increased funding for palliative care and hospices.
Other key Christian figures have been responding to the vote.
Gavin Calver, CEO of the Evangelical Alliance, said he was "deeply disappointed" by the development.
"This is the biggest proposed change to our social fabric in a generation," he said.
"Over recent weeks we have stood side by side with other faith groups, disability groups, medics, lawyers, and countless members of the public highlighting the significant shortcomings of this bill.
“Sadly, this bill will normalise suicide in our society as a positive option and places the most vulnerable at risk of abuse and coercion. We will continue to work to ensure that the bill does not become law.
"Many of those who voted in favour expressed concerns about safeguards and the workability of the law. In the coming months, as the bill is considered further, we will continue to engage and hold MPs to account if their hopes for the bill’s improvement are not met.
“When the bill returns for further votes next year, we will continue to campaign against the principle of this bill and advocate for the best protections for the most vulnerable in our society.”
Ross Hendry, CEO of Christian Action Research and Education (CARE) commented:
“Today’s vote is deeply troubling, particularly for vulnerable and marginalised people in England and Wales who are fearful of a change in the law.
“Legalising assisted suicide would diminish the value we ascribe to human life in our legislation and our institutions and create a two-tier society where suicide prevention doesn’t extend to all people. This would be a moral failure, and a huge step backwards.
“As with other assisted suicide Bills in the past, there are no safeguards in this Bill that will rule out coercion of vulnerable people, and people ending their lives because they feel like a burden or lack proper support. There is no such thing as a ‘safe’ assisted suicide law.
“Parliament does have a responsibility to build better support for those who are dying but not through this dangerous Bill. We need a national conversation on how we ensure excellent, universally accessible end-of-life and palliative care, and stronger support for marginalised groups.
“We would urge parliamentarians to focus on this positive endeavour, and dismiss the dangerous, and disproven campaign for assisted suicide.”
Responding to the vote, the Bishop of London, Rt Rev Sarah Mullally, called for a greater focus on palliative care.
"The Church of England believes that the compassionate response at the end of life lies in the provision of high quality palliative care services to all who need them," she said.
"Today's vote still leaves the question of how this could be implemented in an overstretched and under-funded NHS, social care and legal system.
"In the wake of the decision MPs have made, safeguarding the most vulnerable must now be our priority in the Parliamentary process to come."
The initial parliamentary vote in favour of the bill will start months of debate and the bill could be changed as it makes its way through both the House of Commons and the upper house of parliament, the House of Lords.
Ms Leadbeater has said she expects the process to take a further six months.
The proposal has stirred a national debate in Britain, with former prime ministers, faith leaders, medics, judges, the disabled and ministers in Prime Minister Keir Starmer's Labour government weighing in on the subject.
Polls suggest a majority of Britons back assisted dying.
