Faith leaders in the United Kingdom have joined one another to oppose the legalisation of assisted suicide ahead of a debate in their Parliament.

The Archbishop of Canterbury, leader of the Church of England, the Chief Rabbi in the UK and the head of the Roman Catholic Church in England and Wales expressed grave concerns about the risk to vulnerable people if assisted suicide is legalised.

Former British Prime Minister Gordon Brown also joined in the opposition and warned that passing a law to allow assisted dying would "undermine the sanctity of life" and lead to a slippery slope in which the frail are pressurised to end their lives, The Times reported on Oct. 21.

Brown joined the UK's Chief Rabbi, the Archbishop of Canterbury and the most senior Roman Catholic cardinal in Britain in opposing the private member's bill, which is due to be debated for a second time in the House of Lords.

In an editorial article for UK Times, Brown said that the focus of the medical profession should be in alleviating suffering, and that the "cold, bureaucratic directives" of the proposed law could change the way Britons view doctors and nurses.

The warning came ahead of the debate on the ssisted Dying Bill in the House of Lords, the higher chamber of the UK legislature on Oct. 15, Chrisitian Today reported.

The law under discussion, is modeled on similar legislation in the U.S. state of Oregon and was and was introduced into UK upper chamber in May, Vatican News reported.

It follows a previous bill presented in 2014 which was not able to progress further due to the 2015 UK General Election at the time.

The law under discussion proposes allowing terminally ill people with less than six months to end their lives by assisted suicide.

In a joint letter to upper house representatives Anglican leader Archbishop Justin Welby, Catholic Cardinal Vincent Nichols and Chief Rabbi, Ephraim Mirvis, called for the focus to be on "assisted living" rather than assisted dying.

They raised doubts about promised safeguards as they warned that the common good would not be served by placing the vulnerable in ever more vulnerable positions.

They shared "profound disquiet" over the proposals, and instead called for a compassionate society that offers high-quality palliative care for people in the final months of life.

"By the faiths we profess, we hold every human life to be a precious gift of the Creator, to be upheld and protected," they said.

"All people of faith, and those of none, can share our concern that the common good is not served by policies or actions that would place very many vulnerable people in more vulnerable positions.

"We appeal to people of whatever faith or belief to join us through our common bond of humanity in caring for the most vulnerable people within our society.

"In contrast to the proposals in this Bill, we continue to call for measures to make high-quality palliative care available to all at the end of their lives.

"We believe that the aim of a compassionate society should be assisted living rather than an acceptance of assisted suicide."