Labour MP Trevor Mallard, who in 2003 voted against the Death with Dignity Bill, has come out in support of legalising euthanasia or assisted suicide.
Following the release of a major UK report to parliament advising euthanasia should be legal, Mallard posted on Labour's Red Alert blog that his view has "firmed on the issue over the last decade ..."
He says unless evidence to a select committee highlighted something he is not currently aware of, or if there was a major drafting error, he would "support a bill through all stages."
Meanwhile, a major new report in the UK has said MPs should consider changing the law on assisted suicide to allow some terminally ill people to end their lives at home with the help of their doctor.
The Commission on Assisted Dying, chaired by the former lord chancellor Lord Falconer, says a choice to end their own lives could be safely offered to some people with terminal illnesses, provided stringent safeguards were observed.
Describing the current law on assisted dying as "inadequate and incoherent", the commission will outline a legal framework that would permit only those who had been diagnosed with less than a year to live to seek an assisted suicide, and then only if they met strict eligibility criteria. These would include:
• Two independent doctors were satisfied with the diagnosis.
• The person was aware of all the social and medical help available.
• They were making the decision voluntarily and with no sense of being pressurised by others or feeling "a burden".
• They were not acting under the influence of a mental illness, and were capable of taking the medication themselves, without help.
The 400-page report follows a year of investigation by the commission, whose members also include the former Metropolitan police commissioner Lord Blair, a former president of the General Medical Council, a leading consultant in disability equality, an Anglican priest, and medical, mental health, palliative care and social care specialists.
It was commissioned by the campaign group Dignity in Dying and funded by the author Terry Pratchett, who has Alzheimer's disease, and Bernard Lewis, a businessman. Falconer said he and his fellow commissioners had been "absolutely clear" that they would participate only if they were entirely independent. Under the report's recommended legal framework, Pratchett would be unlikely to be eligible for assistance to die.
Assisted suicide remains a criminal offence in England and Wales, punishable by up to 14 years in prison. Guidelines were introduced in 2010, however, recommending that those helping loved ones to die should not be prosecuted, a legal fudge that was "very, very unsatisfactory", Falconer told the Guardian.
"The choice is whether or not vulnerable people are better protected by the current law, where the only safeguard is the threat of prosecution, or whether or not the stringent safeguards we envisage where two doctors look at it before the person has committed suicide, whether they provide better protection than the current law."
Debbie Purdy, who has progressive multiple sclerosis and whose legal campaign led to the changes in prosecutors' recommendations, welcomed the report and called on MPs to implement its proposed legal framework immediately, even though she would not immediately benefit from the proposals, having an incurable rather than terminal illness.
"I think it should go further, but that needs a lot more discussion," she said. "I think we have the capacity as an intelligent group of people to make a law which will protect [vulnerable people]."
Sarah Wootton, chief executive of Dignity in Dying, said: "We are confident that the evidence and safeguards in this report will reassure those with genuine concerns about the impact of an assisted dying law on society, as the report highlights that such a law would better protect both those who do want more choice and control at the end of their lives, and those who may be vulnerable and need to be safeguarded."
Dr Peter Saunders, of Care Not Killing, said the law did not need changing. "What the commission is proposing is a less safe version of the highly controversial Oregon law, which sees the terminally ill offered drugs to kill themselves, but not expensive lifesaving and life-extending drugs," he said. "Its so-called 'proposed safeguards' are paper-thin and have already been rejected three times in the last six years by British parliaments." Phil Friend, of the Not Dead Yet campaign group, said: "There isn't a route to 'safely' offer a choice of assisted dying to people, whatever the criteria."
Alongside any future legal change, the report argues: "The provision of high quality end-of-life care must be a priority for government, independent of the issue of assisted dying. It recommends that in parallel with any change in the law, the government should also take action to tackle inequalities in end-of-life care and ensure that good quality end-of-life care is available to every person approaching the end of their life."
The Ministry of Justice said: "The government believes that any change to the law in this emotive and contentious area is an issue of individual conscience and a matter for parliament to decide rather than government policy."