As a few low murmurs broke out in a respectfully reflective House of Commons chamber after its historic vote on assisted dying in England and Wales, one figure in the public gallery had a special interest in the result. Back in 2015, Rob Marris, the former Labour MP for Wolverhampton South West, had tabled the previous attempt to pass a bill changing the law. It was comprehensively defeated. On Friday, he returned to the Commons for the first time since departing as an MP in 2017. The bill being discussed was remarkably similar to the one he had presented nine years earlier, but he and other advocates for assisted dying desperately hoped that sentiment among MPs had shifted. As the debate progressed and a series of MPs gave thoughtful and heartfelt speeches against any change in the law, Marris feared the opportunity would again be lost for another decade. So when the vote’s result arrived after five hours of dignified but impassioned discussion, it came as a surprise. “People who I expected to support the bill were not doing so in their speeches,” he said, moments after leaving the chamber. “I thought that maybe the tide was not with us. But there is still a long way to go on this bill.” He and other MPs who were present for the last vote on the issue noticed a satisfying symmetry after Friday’s vote. In 2015, 330 MPs voted against assisted dying for terminally ill people. Last week, 330 voted in favour of the bill presented by Labour backbencher Kim Leadbeater. That reversal was taken by some MPs as a neat reflection of a debate that had reached a tipping point. Yet just as Marris warned, others supportive of the idea now say that the hard work must continue to hold on to wavering MPs. For those in favour of change, the vote was a moment in which parliament finally reflected the long-held views of the public. Polls have regularly shown a majority in favour of assisted dying. The latest Opinium poll for the Observer found that almost two-thirds (64%) support making it legal for someone to seek assisted dying, while a fifth (19%) are opposed. But the current campaign to hand the right of assisted dying to terminally ill people with six months left to live gained serious traction over the past year. It began last December, with interventions from two public figures from outside Westminster. First, the Observer revealed that actor Diana Rigg had made an impassioned case to legalise assisted dying in a message recorded shortly before her “truly awful” and “dehumanising” death from cancer in 2020. Just days later, television presenter Esther Rantzen, who has lung cancer, revealed she had joined the Dignitas assisted dying clinic in Switzerland. Backing a change in England and Wales, she said there should be a choice over “how you want to go and when you want to go”. Meanwhile, former health secretaries Stephen Dorrell and Alan Milburn said they were backing a change. Crucially, Labour confirmed that, should it win power, it would make time and expert advice available for an assisted dying bill if MPs backed it in a free House of Commons vote. Keir Starmer had backed Marris’s bill back in 2015 and remains supportive of a new law. Momentum built in July, when Charles Falconer, who was lord chancellor in Tony Blair’s government and had first adopted the issue of assisted dying in 2013, introduced a private members’ bill to the House of Lords. But he and other campaigners knew that it was a vote in the Commons that was really needed to have any real prospect of success. By the autumn, the issue had become a regular public debating point. Yet it is a quirk of Westminster’s obscure traditions that when the opportunity for this sea change in social policy arose, it came not through public pressure, but via a small ball printed with the number 238. The ball – one of 458 in a bowl – was picked out at random in mid-September as part of the raffle to decide which MPs would have the chance to present their own private members’ bills. Leadbeater’s came out on top. Tory MP Nusrat Ghani, who had the task of picking out the balls, reacted with unerring prescience. “Well done to Kim,” she said. “You are No 1 and you’ll be, gosh, very busy indeed.” When it came, it was a vote that divided the closest of fellow travellers. Leftwing flag bearers John McDonnell and Jeremy Corbyn found themselves entering different division lobbies – one of the rarest of political occasions. McDonnell had recently reached the decision that he was ready to vote in favour of giving people more choice over how they die, while Corbyn continued to worry about safeguards. Meanwhile, Nigel Farage voted against the bill, but his deputy and former Reform UK leader, Richard Tice, voted in favour. Parties split, the cabinet split – and even families found themselves divided. Danny Kruger, a leading opponent of what he described as “assisted suicide”, is at odds with his mother, the television presenter Prue Leith. Yet the only real political fallout has been some anger aimed at Wes Streeting, the health secretary, who spoke out against the bill. Ministers had been advised to stay out of the public debate. While Streeting has talked openly of his fears about a “chilling slippery slope”, some in the party believe he sees it as a significant distraction from his huge task of reforming the NHS to bring down waiting times. But overall, there was broad agreement that last week’s considered debate showed parliament at its best. “I kept saying to colleagues that it would be a day where parliament shows itself in that way,” said one cabinet minister. “It nearly always does that at these moments. I knew there’d be no shenanigans.” Friday’s passing of the second reading of the bill is in itself a historic moment but, as Marris and others have said, obstacles remain before it becomes law, and the hard work for Leadbeater and other leading advocates still lies ahead. All sides of the debate now agree that proper time should be given to the bill to ensure that expert evidence is given, impact assessments are carried out and it is improved line by line where necessary. That will mean it will be studied and scrutinised by a cross-party committee for months, before re-emerging in parliament in about April. The 55-strong majority returned in the vote is seemingly robust in normal parliamentary terms, but the bill’s passage into law cannot yet be guaranteed. Some MPs backed the bill in order to continue the debate and are awaiting reassurances before voting it into law. Among them is former Brexit secretary David Davis, though the Observer has heard from other MPs in the same position. There are also the 31 MPs who did not record a vote, who could yet be crucial. More granular debates lie ahead. Looking back on Friday’s events, however, some of those involved in the assisted dying debate for years reflected on the fact that even with so many new MPs in parliament, almost all of them opted to grapple with the issue and take a view. “If that is the template for this parliament, it’s going to be a very, very impressive parliament,” said Lord Falconer. “Whatever else happens in this parliament, it will be remembered for this incredibly historic change.”