The UK is “behind the curve” among progressive nations, the assisted dying bill’s sponsor, Kim Leadbeater, has said on the eve of one of the most consequential votes for social change in England and Wales.The Labour MP said the circumstances may never be right again to pass such a bill, which would legalise assisted dying in England and Wales for terminally ill people with less than six months to live, subject to approval by two doctors and a panel of experts.Her intervention came amid more warnings about the safeguards in the bill, including from the Royal College of Psychiatrists and disability activists, who will protest outside parliament on Friday at the final vote in the Commons.Opponents believe the bill will not offer sufficient protection to those with mental illness or disability or those who might be coerced by abusers.On Thursday, another leading Labour MP, Dan Carden, said he would vote against the bill and the Conservative leader, Kemi Badenoch, urged her MPs to oppose it.

Keir Starmer has reiterated his own support for the bill, but on Thursday night there was no firm commitment from No 10 that the prime minister would be present to vote.“We are behind the curve,” Leadbeater said.“We’ve got the law going through the Isle of Man.We’ve got Jersey.We’ve got France.

We’ve got various American states, Colorado recently.“Other countries are looking at us and saying, goodness me, why are you not doing what is essentially the right thing to do? And if we don’t do it now, we could be looking at another 10 years.We cannot put families through another 10 years of that.”The MP for Spen Valley said circumstances may never allow such a change for another generation, given the number of progressive MPs in the parliament.“This is surely everything modern parliamentarians should believe in: big societal change for the people that need it,” she said.

“Now is the time,”Should the bill pass, Leadbeater said it would be accessible to those with a terminal illness by the end of the parliament, with a four-year implementation period,“I will certainly be putting pressure on to commence sooner than that if it can be done safely and effectively,” she said,“But ultimately it’s about it being safe rather than rushing it through,”At least 19 MPs have publicly said they will switch sides from either abstaining or backing the bill to voting against.

Since the bill was last voted on, there has been a major change to the legislation: the removal of the requirement for a high court judge to sign off each case, replaced by a panel of experts including a psychiatrist, a social worker and senior lawyer.Proponents of the bill claimed they were confident it would pass again on Friday, having previously passed with a majority of 55.But further high-profile switchers or even significant interventions in the chamber on Friday could be critical and those who oppose the bill said they believed there was still significant traffic in their direction.Campaigners on both sides said that MPs would be going to extraordinary lengths to make the vote, returning from hospital bedsides and long-haul trips.Carden, who leads the Blue Labour group of MPs, told the Guardian he would vote against, having previously abstained.

“Legalising assisted suicide will normalise the choice of death over life, care, respect and love,” the MP for Liverpool Walton said.“I draw on my own family experience, caring for my dad who died from lung cancer three years ago.“I genuinely fear the legislation will take us in the wrong direction.The values of family, social bonds, responsibilities, time and community will be diminished, with isolation, atomisation and individualism winning again.”Those who have switched from previously supporting the bill to voting against include the Conservative former minister George Freeman, the Lib Dem work and pensions spokesperson, Steve Darling, and the Labour MPs Karl Turner, Kanishka Narayan and Jonathan Hinder.

But there have been some who have moved to vote in favour, including the Ipswich Labour MP Jack Abbott, who voted against in November but switched to support having been on the bill’s scrutiny committee, saying he was now convinced the safeguards were robust,A YouGov poll on the eve of the vote found assisted dying has robust support among the UK public: 75% believe that assisted dying should in principle be legal in some form in the UK, compared with 14% opposed,But there are significant divisions across different sections of society,Polling for the Muslim Council of Britain showed British Muslims were overwhelmingly likely to oppose the bill,The poll found 70% of respondents said that if their local MP were to vote for the assisted suicide bill, it would make them less likely to vote for them at the next election.

Badenoch urged Conservative MPs to vote against the bill, though it remains a free vote,“I’m somebody who has been previously supportive of assisted suicide,” she said,“This bill is a bad bill,It is not going to deliver,It has not been done properly.

“This is not how we should put through legislation like this.I don’t believe that the NHS and other services are ready to carry out assisted suicide, so I’ll be voting no, and I hope as many Conservative MPs as possible will be supporting me in that.”The Royal College of Psychiatrists issued another warning before the vote, saying there were “too many unanswered questions about the safeguarding of people with mental illness”.Should the bill pass on Friday, it will then go to the House of Lords.However, it is not expected peers will block its progress once the Commons has passed the bill, though it may be amended.

The Labour peer Luciana Berger urged MPs to vote against the bill if they were unsure about safeguards, rather than assume further changes would be made in the Lords.“Elected MPs should be clear that as it is a [private member’s bill], amendments are likely to be limited,” she posted on X.“MPs must be satisfied that the Bill in front of them on Friday is fit for purpose.”The Labour peer Charlie Falconer is likely to take charge of the bill in the House of Lords.Falconer had submitted his own bill to the Lords prior to Leadbeater’s, though he withdrew it when her bill was put to the Commons.

Proponents of the bill hope it will receive royal assent by October, but there will be a four-year implementation period to allow the NHS, Department of Health and Social Care and the Ministry of Justice to develop procedures and guidance.It is – as yet – unclear if the procedure would be available on the NHS or free at the point of use.