Only one in three MPs supports changing UK laws to allow assisted suicide, a new poll has found. 

The figures from YouGov, gathered as part of its monthly MP Omnibus survey, found that overall only 35% supported allowing "doctors to assist in the suicide of someone suffering from a terminal illness". 

Conservative MPs were the least likely to support such a change, with only 30% in favour. 

When asked if they would support assisted suicide for someone suffering from a "painful, incurable but NOT terminal illness", only 16% said they would. 

The MP Omnibus survey interviewed 100 MPs from across the parties. 

The poll was conducted as peers in the House of Lords consider Baroness Meacher's Assisted Dying Bill that proposes legalising assisted suicide for terminally ill, mentally competent adults deemed to be in the last six months of their life as long as they have the permission of two doctors and a High Court judge. 

The Bill has already had its first reading in the Lords and is expected to have its second reading in the autumn. 

The last time Parliament considered legalising assisted suicide was in 2015 with the Marris-Falconer Assisted Dying Bill that was defeated by a large majority of 330 votes to 118.

Opponents have warned of a slippery slope once assisted suicide is legal. 

This has been seen in countries like the Netherlands and Belgium where laws have been increasingly expanded to include children and those with mental health issues. 

In Canada, the parliament recently passed Bill C-7 that expands euthanasia legislation to include people with disabilities and mental health issues. 

The Catholic Bishop of Shrewsbury, Mark Davies, is urging Westminster not to change the law. 

He said "we should be in no doubt as to the moral line that would be crossed" if Parliament legalises assisted suicide. 

"A line that has never been legally crossed in our care of the sick and elderly since the foundation of our society. The culture built on the commandment 'You shall not kill' has protected the most vulnerable, led to the development of the finest end of life care and never required of our medical and nursing professions that they assist in the suicide or the killing of their patients," he said.

"I urge all those who value the sanctity of human life and desire the best care and support for the sick and the dying, to oppose this latest proposal to cross the line from caring towards killing."

Right to Life UK welcomed the broad opposition among MPs. 

Spokesperson Catherine Robinson said, ""It is wonderful to see that so many MPs are speaking sense on this issue, especially as we anticipate the return of Baroness Meacher's Bill to Parliament this autumn," adding that "what vulnerable people need at the end of their lives is love and support, not offers to assist their death".