Campaigners have warned of "harm" and "profound injustices" following the publication of a Commons report that suggests the law on assisted suicide is likely to change in parts of the UK soon.
A report from the parliamentary Health and Social Care Committee says that UK ministers must consider the implications of legal divergence on the matter.
The report has been published as Scotland, Jersey and the Isle of Man prepare to consider fresh proposals aimed at legalising assisted suicide.
Jersey, a Crown Dependency with its own legislature and laws, has been tipped to become the first place in the British Isles to legalise assisted suicide.
Responding to the Commons report, Christian social policy charity CARE warned that legalising assisted suicide would "harm UK society as a whole".
CARE policy director, Louise Davies, said that the "cross-border effects" of changing the law in some parts of the UK "have not been considered".
"A law change in Scotland, for example, would create huge challenges for suicide prevention in England. Scotland may also see an influx of people, compounding pressure on its NHS," she said.
Davies expressed scepticism about safeguarding promises, saying that they "always fail".
"We believe that assisted suicide is not something that should be countenanced in any area of the UK," she said.
"Evidence from other jurisdictions paints a troubling picture. In Canada, for example, marginalised people feel forced to end their lives because they cannot access the services they need to live. And this has become accepted.
"Assisted suicide legislation in the UK would lead to the same profound injustices, and damage UK society as a whole."
She added, "Safeguards always fail: doctors cannot detect the subtle signs of coercion, and may miss them altogether.
"The law could become more permissive over time: activists would demand assisted suicide for people who don't have a terminal illness before long. The current approach is best, and consistency is best. We would urge politicians to say no."
Dr Gordon Macdonald, chief executive of Care Not Killing, a campaign group opposed to assisted suicide, expressed disappointment that MPs have not come down firmly against changing the law in light of serious concerns, which include vulnerable people feeling pressured to end their lives and restrictions being "swept away".
"There are many problems with changing the law to legalise state sanctioned killing," he said.
"As we saw in the Netherlands and Belgium, limits on who qualifies for an assisted death have been swept away. No longer is state-aided killing with death row drugs limited to those with less than six months to live, but routinely includes disabled people, those with chronic non-terminal conditions and individuals with mental health problems, such as patients with dementia, treatable depression, anorexia, even a victim of sexual abuse."
He continued, "At a time when we have seen how fragile our health care system is, how underfunding puts pressure on services, accessing specific treatments and when the UK's amazing hospice movement faces a £100 million funding crisis, MPs could have decided to firmly close the door on assisted suicide and euthanasia, and say the current law which protects everyone, regardless of whether they are young or old, able bodied or disabled should remain. They failed."
