Friday’s vote by British MPs in favour of legalising assisted dying is the first step towards landmark legislation that would mean terminally ill adults wishing to end their lives can legally be helped to do so in England and Wales for the first time. The vote passed by 330 votes to 275, a clear but not overwhelming margin, reflecting the often passionately held positions on each side of the debate. Campaigners in favour of the change had argued that the legislation offered a rare opportunity to give choice and dignity to people who wanted to end their own lives, under strictly limited circumstances. But many of those who had opposed it expressed fears that it could allow vulnerable people to be coerced into opting for an early death. Others had argued that efforts should instead be directed to improving palliative and end of life care. The vote is a watershed in what has been an intensely debated subject in the UK for decades. Polls show a majority of the public support legalising the measure. The bill passed by MPs proposes that terminally ill adults who are expected to die within six months and wish to hasten their death can be helped to do so by a doctor. Those supporting the bill insist it includes tough safeguards to prevent sick people being put under pressure to end their own lives. Under the proposals, a person living in England or Wales who wants to be helped to end their life must be over 18, be expected to die within six months and have the mental capacity to decide. They must make two separate declarations, witnessed and signed, about their wish to die, to the satisfaction of two independent doctors and a high court judge. While a doctor would prepare the substance being used to end life, the person would have to take or administer it themselves. It would be illegal to pressurise someone to take this step, with a penalty of up to 14 years in prison. The legislation does not apply in Scotland or Northern Ireland. The vote was introduced not as part of the government’s business but as a private member’s bill. This is a lottery system by which MPs are able to propose measures that fall outside the government’s agenda if their names are drawn at the top of a ballot. Kim Leadbeater, the Labour MP behind the bill, came first in the ballot in September. While most private members’ bills go nowhere, Leadbeater opted to propose a measure on which MPs last voted in 2015 – then, a previous assisted dying bill was comprehensively rejected. She has compared the campaign for assisted dying to the push to allow a woman the right to choose an abortion, arguing that terminally ill people should be given similar autonomy over their bodies. The landmark 1967 Abortion Act, which legalised abortion in Britain with limitations, was also introduced as a private member’s bill. It was a “free” vote, meaning individual MPs were allowed to vote according to their conscience, rather than along party lines communicated by a government whip. The prime minister, Keir Starmer, voted in favour, but the deputy prime minister, Angela Rayner, the health secretary, Wes Streeting, and other cabinet ministers opposed it. The opposition Conservative leader, Kemi Badenoch, who voted against, had said she supported assisted dying in principle but could not back the current proposals. Most MPs from the ruling Labour party – 234 out of 402 – voted in favour, but only 23 Conservative MPs out of 121 did so; the previous prime minister, Rishi Sunak, was among them. The vote does not mean the matter is now law. Rather the passing of the “second reading” of the bill – which, despite its name, is the first time representatives have been able to debate and vote on it in parliament – means the proposal passes to the committee stage, the next step of the parliamentary process, at which each clause is examined carefully and any amendments can be debated. This will not happen before next spring. The bill will then be put to another MPs’ vote in the House of Commons before, if passing again, going to the House of Lords. As the law stands at present, assisting a suicide is illegal in England, Wales and Northern Ireland. While it is not explicitly a crime in Scotland, helping someone to die could lead to a charge of culpable homicide. The state has declined to prosecute in some cases, however, leading to uncertainty for terminally ill people who want to choose how and when to die. In 2010, Starmer – at the time the director of public prosecutions or chief public prosecutor for England and Wales – said it was not in the public interest to prosecute a doctor, Michael Irwin, who travelled with a patient to the Dignitas clinic in Zurich where he ended his life. Campaigners have long argued that a parliamentary vote was needed to end the legal ambiguity.