On Friday, MPs will vote on the Terminally Ill Adults (End of Life) bill – a once-in-a-generation vote on whether those with terminal illnesses should have the right to an assisted death. The right, in other words, to end one’s own life with the help of medical professionals.

As the Guardian’s deputy political editor Jessica Elgot explains, it would be a monumental social change, and has been compared to previous reforms on abortion, the death penalty and equal marriage. Yet with just a day to go, it is not at all clear which way the vote will go. Indeed, Helen Pidd hears from MPs in parliament, some of whom are still unsure whether they will support or oppose the bill.

Despite the right to an assisted death consistently proving popular in opinion polls, many across the house are concerned about how to actually implement it in law, in an area fraught with ethical and medical risks – around protecting terminally ill people from pressure or coercion, around safeguarding disabled patients, and around reshaping the relationship between doctors and their patients.

It is a complicated issue, and the vote comes after weeks of increasingly heated arguments. Senior politicians have openly castigated others, for example for imposing their religious beliefs on others. Lucy Thomas, a palliative care and public health doctor, talks through her own concerns – not only about the bill, but about the way it has been debated in public.