Later today politicians will vote on the proposal which would allow a terminally ill person with less than six months left to live the option to end their life early.
Here is a roundup of those for and against the change:
Archbishop of Canterbury, Justin Welby
"The evidence around the world is that there is a slippery slope and that once you cross this line and say that we accept that part of the role of medicine is deliberately to kill people, that there is always pressure to go a little bit further.
"I've watched all kinds of different deaths over time, and as a carer I've done that, and I've felt that sense of 'I wish it was all over' and yet come back to the point that that is not giving life its full value."
Former Archbishop of Canterbury, Lord Carey
"People have said we're afraid of where the legislation might end up, it might lead to very vulnerable people being abused by very cruel and greedy relatives.
"But we can construct laws that are strong, that are resistant and I believe that the unintended consequence is a really bad way of opposing the bill."
Cardinal Vincent Nichols
"The intrinsic value of each human life will be gravely undermined if this or any bill to legalise assisted suicide were to become law.
"Licensing doctors to supply lethal drugs to terminally ill patients to help them commit suicide rests upon the premise that some lives are worth less than others. It is therefore contrary to human dignity."
Bishop of Buckingham, Rt Revd Alan Wilson
"Very, very few people in countries where such laws operate actually use it, and I'm sure that's right - I don't want more people to use it. But the fact that it's there can give them a sense of autonomy and dignity in the face of terminal disease.
"If people turn out to live longer than their prognosis, praise the Lord! Nobody's trying to kill anyone here, that's absolutely delightful. It's the fact they have a possible way out if things did not work out well for them, and that they have some measure of autonomy about that."
General Director of the Evangelical Alliance, Steve Clifford
"As Christians, we believe in the inherent dignity and value of every individual. Legalising assisted suicide could put pressure on vulnerable people to end their lives for fear of being a burden.
"The present law works well and doesn't need changing. It acts as a powerful deterrent to the exploitation of vulnerable people, while also giving discretion to prosecutors and judges in challenging cases."
Canon Rosie Harper
"I thought people would be furious with me for speaking in support of assisted dying, but I've had many people coming up to me to shake my hand and say 'It's what I've always thought'.
"I fear the church leadership will find itself out of step on this issue, just as it did on women bishops."