Disability campaigners have voiced concern about an attempt to change the law on assisted dying as the legislation faced its latest parliamentary hurdle.
But supporters of a change claimed opponents were determined to "strangle" the Assisted Dying Bill by using up the available time when it returns to the House of Lords for detailed scrutiny today.
The c ontroversial proposals by Labour ex-justice secretary Lord Falconer, which would offer the chance of assisted dying to terminally ill patients deemed mentally capable and within six months of likely death, will be considered line-by-line in the legislation's committee stage.
Disability charity Scope's chief executive Richard Hawkes said: "Many disabled people are really worried about a change in the law on assisted suicide.
"They are concerned that it will lead to disabled people, and other vulnerable people, feeling under pressure to end their lives.
"Why is it that when people who are not disabled want to commit suicide, we try to talk them out of it, but when a disabled person wants to commit suicide, we focus on how we can make that possible?
"The campaign to legalise assisted suicide reinforces deep-seated beliefs that the lives of disabled people are not worth as much as other people's. It's a view that is all too common.
"The current law against assisted suicide works. It sends a powerful message countering the view that if you're disabled it's not worth being alive, and that you're a burden.
"Many disabled people strongly oppose a change in the law."
A poll carried out for Scope earlier this year found that 64% of disabled people who expressed an opinion had concerns about legalising assisted suicide, while 36% would not be concerned.
The Opinium study found 55% were concerned that disabled people might chose to end their lives in order not to be a burden on family, friends or caregivers, while 33% were not concerned and 12% said they did not know.
Some 55% said the current ban on assisted suicide "protects vulnerable people from pressure to end their lives", with 19% disagreeing, 22% neither agreeing nor disagreeing and 4% unsure.
The poll of 1,005 disabled adults, carried out between July 7 and 11, also found that 59% of those surveyed agreed that "disabled people's lives are generally not valued as much as other people's".
The Bill was given an unopposed second reading after a marathon debate on the legislation in July which lasted for 10 hours and featured nearly 130 speeches.
Among the backers were former Archbishop of Canterbury Lord Carey who shocked many by declaring he had reversed his opposition - but the issue remains highly controversial and is set to provoke further fierce discussion.
The backbench Bill's chance of progress is limited, as more than 170 amendments have been tabled for debate today, meaning it could fall due to a lack of parliamentary time.
Campaign group Dignity in Dying's chief executive Sarah Wootton said she hoped a majority of peers would "work to make progress" on the issue instead of attempting to talk it out.
She said: " The Assisted Dying Bill was unanimously passed at second reading in the House of Lords and it is imperative that Parliament engages constructively at committee stage.
"In light of the Supreme Court's warning that Parliament must act, along with massive public support for change, it is concerning that opponents of change have set out a strategy to 'strangle the Bill' at Committee stage.
"That said, we remain hopeful that a majority of peers will work to make progress on this important issue.
"Without a change in the law dying Britons will continue to travel to Dignitas, take their own lives behind closed doors in this country, or be illegally helped to die by doctors.
"We need a safeguarded law with adequate safeguards which provides greater protection and gives dying people choice and control at the end of life.
"Parliament decided at second reading that it is a question of how, not if, we legislate on this issue. Turning a blind eye to suffering is no longer an option."